diff --git a/docs/NEWS.md b/docs/NEWS.md
index d745af99..ff2bef6d 100644
--- a/docs/NEWS.md
+++ b/docs/NEWS.md
@@ -12,6 +12,60 @@ See [UPGRADING.md](UPGRADING.md) for more detailed instructions about upgrading
 
 ## New features
 
+### New OneShot features
+
+#### Auto-OneShot modifiers & layers
+
+OneShot can now treat modifiers and layer-shift keys as automatic OneShot
+keys. This includes modifiers with other modifier flags applied, so it is now
+very simple to turn `Key_Meh` or `Key_Hyper` into a OneShot key. The feature is
+controlled by the following new functions:
+
+- `OneShot.toggleAutoModifiers()`: Turn auto-OneShot modifiers on or off.
+- `OneShot.toggleAutoLayers()`: Turn auto-OneShot layer shifts on or off.
+- `OneShot.toggleAutoOneShot()`: Both of the above.
+
+There are also `enable` and `disable` versions of these functions.
+
+Note, it is still possible to define a modifier key in the keymap that will not
+automatically become a OneShot key when pressed, by applying modifier flags to
+`Key_NoKey` (e.g. `LSHIFT(Key_NoKey)`).
+
+#### Two new special OneShot keys
+
+OneShot can now also turn _any_ key into a sticky key, using either of two
+special `Key` values that can be inserted in the keymap.
+
+##### `OneShot_MetaStickyKey`
+
+This is a special OneShot key (it behaves like other OneShot keys), but its
+effect is to make any key pressed while it is active sticky. Press
+`OneShot_MetaStickyKey`, then press `X`, and `X` will become sticky. Sticky
+keys can be deactivated just like other OneShot keys, by pressing them
+again. This works for any key value, so use it with caution.
+
+##### `OneShot_ActiveStickyKey`
+
+Like `OneShot_ActiveStickyKey`, this key makes other keys sticky, but rather than
+affecting a subsequent key, it affects any keys already held when it is
+pressed. Press `X`, press `OneShot_ActiveStickyKey`, and release `X`, and `X`
+will be sticky until it is pressed again to deactivate it. Again, it works on
+any key value, so use with caution.
+
+#### LED-ActiveModColor highlighting
+
+With the updates to OneShot, LED-ActiveModColor now recognizes and highlights
+OneShot keys in three different states (along with normal modifiers):
+
+- one-shot (a key that's active after release, but will time out)
+- sticky (a key that will stay active indefinitely after release)
+- normal (a key that will stay active only while physically held; also applies
+  to normal modifier keys)
+
+The colors of theses three highlights are controlled by the properties
+`ActiveModColorEffect.oneshot_color`, `ActiveModColorEffect.sticky_color`, and
+`ActiveModColorEffect.highlight_color`, respectively.
+
 ### Better protection against unintended modifiers from Qukeys
 
 Qukeys has two new configuration options for preventing unintended modifiers in
diff --git a/docs/UPGRADING.md b/docs/UPGRADING.md
index 87714f0c..6203eb3f 100644
--- a/docs/UPGRADING.md
+++ b/docs/UPGRADING.md
@@ -18,6 +18,7 @@ If any of this does not make sense to you, or you have trouble updating your .in
     - [The `RxCy` macros and peeking into the keyswitch state](#the-rxcy-macros-and-peeking-into-the-keyswitch-state)
     - [HostOS](#hostos)
     - [MagicCombo](#magiccombo)
+    - [OneShot](#oneshot)
     - [Qukeys](#qukeys)
     - [TypingBreaks](#typingbreaks)
     - [Redial](#redial)
@@ -580,6 +581,44 @@ If your actions made use of the `left_hand` or `right_hand` arguments of
 more involved to get to, out of scope for this simple migration guide. Please
 open an issue, or ask for help on the forums, and we'll help you.
 
+### OneShot
+
+Older versions of the plugin were based on `Key` values; OneShot is now based on
+`KeyAddr` coordinates instead, in order to improve reliability and
+functionality.
+
+The following deprecated functions and variables will be removed after
+**2021-04-31**.
+
+#### Deprecated functions
+
+- `OneShot.inject(key, key_state)`: This `Key`-based function still works, but
+  because OneShot keys are now required to have a valid `KeyAddr`, it will now
+  look for an idle key, and use that, masking whatever value was mapped to that
+  key. Most of the reasons for using this function are better addressed by using
+  the newer features of the plugin, such as automatic one-shot modifiers. Use is
+  very strongly discouraged.
+- `OneShot.isActive(key)`: This `Key`-based function no longer makes sense now
+  that OneShot is `KeyAddr`-based. There is a `OneShot.isActive(key_addr)`
+  function that should be used instead. The deprecated function still works, but
+  its use is discouraged.
+- `OneShot.isSticky(key)`: This `Key`-based function no longer makes sense now
+  that OneShot is `KeyAddr`-based. There is a `OneShot.isSticky(key_addr)`
+  function that should be used instead. The deprecated function still works, but
+  its use is discouraged.
+- `OneShot.isPressed()`: This function no longer has any reason for existing. In
+  older versions, the Escape-OneShot companion plugin used it to solve a problem
+  that no longer exists. It now always returns `false`.
+- `OneShot.isModifierActive(key)`: This function still works, but is not
+  perfectly reliable, because it now returns positive results for keys other
+  than OneShot modifiers. It should not be used.
+
+#### Deprecated variables
+
+- `OneShot.time_out`: Use `OneShot.setTimeout()` instead.
+- `OneShot.hold_time_out`: Use `OneShot.setHoldTimeout()` instead.
+- `OneShot.double_tap_time_out`: Use `OneShot.setDoubleTapTimeout()` instead.
+
 ### Qukeys
 
 Older versions of the plugin used `row` and `col` indexing for defining `Qukey`
diff --git a/examples/Keystrokes/OneShot/OneShot.ino b/examples/Keystrokes/OneShot/OneShot.ino
index c5dfdb87..483d2c46 100644
--- a/examples/Keystrokes/OneShot/OneShot.ino
+++ b/examples/Keystrokes/OneShot/OneShot.ino
@@ -21,27 +21,27 @@
 
 // Macros
 enum {
-  OSMALTCTRL,
+  TOGGLE_ONESHOT,
 };
 
 // *INDENT-OFF*
 KEYMAPS(
   [0] = KEYMAP_STACKED
   (
-    Key_NoKey,    Key_1, Key_2, Key_3, Key_4, Key_5, Key_NoKey,
+    M(TOGGLE_ONESHOT), Key_1, Key_2, Key_3, Key_4, Key_5, OneShot_MetaStickyKey,
     Key_Backtick, Key_Q, Key_W, Key_E, Key_R, Key_T, Key_Tab,
     Key_PageUp,   Key_A, Key_S, Key_D, Key_F, Key_G,
     Key_PageDown, Key_Z, Key_X, Key_C, Key_V, Key_B, Key_Escape,
 
     OSM(LeftControl), Key_Backspace, OSM(LeftGui), OSM(LeftShift),
-    M(OSMALTCTRL),
+    Key_Meh,
 
-    Key_skip,  Key_6, Key_7, Key_8,     Key_9,      Key_0,         Key_skip,
+    OneShot_ActiveStickyKey, Key_6, Key_7, Key_8, Key_9, Key_0,    ___,
     Key_Enter, Key_Y, Key_U, Key_I,     Key_O,      Key_P,         Key_Equals,
                Key_H, Key_J, Key_K,     Key_L,      Key_Semicolon, Key_Quote,
-    Key_skip,  Key_N, Key_M, Key_Comma, Key_Period, Key_Slash,     Key_Minus,
+    ___,       Key_N, Key_M, Key_Comma, Key_Period, Key_Slash,     Key_Minus,
 
-    OSM(RightShift), OSM(RightAlt), Key_Spacebar, OSM(RightControl),
+    Key_RightShift, Key_RightAlt, Key_Spacebar, Key_RightControl,
     OSL(1)),
 
   [1] = KEYMAP_STACKED
@@ -64,14 +64,13 @@ KEYMAPS(
 )
 // *INDENT-ON*
 
-void macroOneShotAltControl(uint8_t keyState) {
-  OneShot.inject(OSM(LeftAlt), keyState);
-  OneShot.inject(OSM(LeftControl), keyState);
+void macroToggleOneShot() {
+  OneShot.toggleAutoOneShot();
 }
 
 const macro_t *macroAction(uint8_t macroIndex, uint8_t keyState) {
-  if (macroIndex == OSMALTCTRL) {
-    macroOneShotAltControl(keyState);
+  if (macroIndex == TOGGLE_ONESHOT) {
+    macroToggleOneShot();
   }
 
   return MACRO_NONE;
diff --git a/plugins/Kaleidoscope-LED-ActiveModColor/README.md b/plugins/Kaleidoscope-LED-ActiveModColor/README.md
index 16dc6ba2..e2a2c709 100644
--- a/plugins/Kaleidoscope-LED-ActiveModColor/README.md
+++ b/plugins/Kaleidoscope-LED-ActiveModColor/README.md
@@ -2,9 +2,8 @@
 
 With this plugin, any active modifier on the keyboard will have the LED under it
 highlighted. No matter how the modifier got activated (a key press, a macro,
-anything else), the coloring will apply. Layer keys, be them layer toggles,
-momentary switches, or one-shot layer keys count as modifiers as far as the
-plugin is concerned.
+anything else), the coloring will apply. Layer shift keys and OneShot layer keys
+count as modifiers as far as the plugin is concerned.
 
 ## Using the plugin
 
@@ -37,11 +36,20 @@ properties:
 
 ### `.highlight_color`
 
-> The color to use for highlighting the modifiers. Defaults to a white color.
+> The color to use for highlighting normal modifier keys and
+> layer-shift keys. Defaults to a white color.
+
+### `.oneshot_color`
+
+> The color to use for highlighting active one-shot keys. These are
+> the keys that will time out or deactivate when a subsequent key is
+> pressed. Defaults to a yellow color.
 
 ### `.sticky_color`
 
-> The color to use for highlighting one-shot modifiers when they are sticky. Defaults to a red color.
+> The color to use for highlighting "sticky" one-shot keys. These keys
+> will remain active until they are pressed again. Defaults to a red
+> color.
 
 ## Plugin methods
 
diff --git a/plugins/Kaleidoscope-OneShot/README.md b/plugins/Kaleidoscope-OneShot/README.md
index 539b997e..f0e8699d 100644
--- a/plugins/Kaleidoscope-OneShot/README.md
+++ b/plugins/Kaleidoscope-OneShot/README.md
@@ -23,7 +23,7 @@ active if another one-shot of the same type is tapped, so `Ctrl, Alt, b` becomes
 `Ctrl+Alt+b`, and `L1, L2, c` is turned into `L1+L2+c`. Furthermore, modifiers
 and other layer keys do not cancel the one-shot effect, either.
 
-## Using One-Shot Keys
+## Using One-Shot keys
 
 To enter one-shot mode, tap _quickly_ on a one-shot key. The next
 normal (non-one-shot) key you press will have the modifier applied,
@@ -40,11 +40,30 @@ modifier will now stay on until you press it again. Continuing the
 Shift, d, e, f` will give you `ABCdef`.
 
 This can be a bit tricky; combining this plugin with
-[LED-ActiveModColor](Kaleidoscope-LED-ActiveModColor.md)
-will help you understand what state your one-shot is in; when a
-one-shot key is active, it will have a white LED highlight; when
-sticky, a red highlight. (These colors are configurable.)
+[LED-ActiveModColor](Kaleidoscope-LED-ActiveModColor.md) will help you
+understand what state your one-shot is in; when a one-shot key is active, it
+will have a yellow LED highlight; when sticky, a red highlight. When it is in a
+"held" state, but will be deactivated when released like any non-one-shot key,
+it will have a white highlight. (These colors are configurable.)
 
+## Special OneShot keys
+
+OneShot also comes with two special keys that can make any key on your keyboard
+sticky: `OneShot_MetaStickyKey` & `OneShot_ActiveStickyKey`. These are both
+`Key` values that can be used as entries in your sketch's keymap.
+
+### `OneShot_MetaStickyKey`
+
+This special OneShot key behaves like other OneShot keys, but its affect is to
+make the next key pressed sticky. Tap `OneShot_MetaStickyKey`, then tap `X`, and
+`X` will become sticky. Tap `X` again to deactivate it.
+
+### `OneShot_ActiveStickyKey`
+
+This special key doesn't act like a OneShot key, but instead makes any key(s)
+currently held (or otherwise active) sticky. Press (and hold) `X`, tap
+`OneShot_ActiveStickyKey`, then release `X`, and `X` will stay active until it
+is tapped again to deactivate it.
 
 ## Using the plugin
 
@@ -69,13 +88,13 @@ void setup() {
 
 There are two macros the plugin provides:
 
-### `OSM(mod)`
+#### `OSM(mod)`
 
 > A macro that takes a single argument, the name of the modifier: `LeftControl`,
 > `LeftShift`, `LeftAlt`, `LeftGui` or their right-side variant. When marked up
 > with this macro, the modifier will act as a one-shot modifier.
 
-### `OSL(layer)`
+#### `OSL(layer)`
 
 > Takes a layer number as argument, and sets up the key to act as a one-shot
 > layer key.
@@ -83,85 +102,203 @@ There are two macros the plugin provides:
 > Please note that while `Kaleidoscope` supports more, one-shot layers are
 > limited to 8 layers only.
 
+In addition, there is a special key:
+
+#### `Key_MetaSticky`
+
+> A key that behaves like a one-shot key, but while active, it makes
+> other keys that are pressed become sticky, just like double-tapped
+> one-shot keys.
+
 ## Plugin methods
 
 The plugin provides one object, `OneShot`, which implements both one-shot
 modifiers and one-shot layer keys. It has the following methods:
 
-### `.isActive()`
+### Configuration methods: Timeouts
 
-> Returns if any one-shot key is in flight. This makes it possible to
-> differentiate between having a modifier or layer active, versus having them
-> active only until after the next key getting pressed. And this, in turn, is
-> useful for macros that need to fiddle with either modifier or layer state: if
-> one-shots are not active, they need not restore the original state.
+#### `.setTimeout(timeout)`
 
-### `.isPressed()`
+> OneShot keys will remain active after they're pressed for `timeout`
+> milliseconds (or until a subsequent non-oneshot key is pressed). The
+> default value is 2500 (2.5 seconds).
 
-> Returns true if any one-shot key is still held.
+#### `.setHoldTimeout(timeout)`
 
-### `.isSticky(key)`
+> If a one-shot key is held for longer than `timeout` milliseconds, it
+> will behave like a normal key, and won't remain active after it is
+> released. The default value is 250 (1/4 seconds).
 
-> Returns if the key is currently sticky.
+#### `.setDoubleTapTimeout(timeout)`
 
-### `.isModifierActive(key)`
+> If a one-shot key is double-tapped (pressed twice in a row) in less
+> than `timeout` milliseconds, it wil become sticky, and will remain
+> active until it is pressed a third time. The default value is -1,
+> which indicates that it should use the same timeout as
+> `.setTimeout()`.
 
-> Returns if the modifier `key` has a one-shot state active. Use this together
-> with `Kaleidoscope.hid().keyboard().isModifierKeyActive` to catch cases where
-> a one-shot modifier is active, but not registered yet.
+### Configuration methods: Stickability
 
-### `.cancel([with_stickies])`
+#### `.enableStickability(key...)`
+#### `.disableStickability(key...)`
 
-> The `cancel()` method can be used to cancel any pending one-shot effects,
-> useful when one changed their minds, and does not wish to wait for the
-> timeout.
+> Enables/disables stickability for all keys listed. The keys should
+> all be OneShot keys, modifier keys, or layer-shift keys, as
+> specified on the keymap. For example:
+> `OneShot.enableStickability(OSM(LeftShift), OSL(1), Key_RightGUI)`.
+> `OneShot.disableStickability(OSM(RighttAlt), OSL(2), ShiftToLayer(4))`.
 >
-> The optional `with_stickies` argument, if set to `true`, will also cancel
-> sticky one-shot effects. If omitted, it defaults to `false`, and not canceling
-> stickies.
+> By default, all OneShot keys are stickable.
 
-### `.inject(key, keyState)`
+#### `.enableStickabilityForModifiers()`
+#### `.enableStickabilityForLayers()`
+#### `.disableStickabilityForModifiers()`
+#### `.disableStickabilityForLayers()`
 
-> Simulates a key event, specifically designed to inject one-shot keys into the
-> event loop. The primary purpose of this method is to make it easier to trigger
-> multiple one-shots at the same time.
->
-> See the example sketch for more information about its use.
+> Enables/disables stickability for all modifiers and layers,
+> respectively. These are convenience methods for cases where one
+> wants to enable stickability for a group of one-shot keys.
 
-### `.enableStickability(key...)`
+### Configuration methods: Automatic one-shot keys
 
-> Enables stickability for all keys listed. The keys should all be OneShot keys,
-> as if specified on the keymap. For example:
->   `OneShot.enableStickability(OSM(LeftShift), OSL(1))`.
->
-> By default, all oneshot keys are stickable.
+#### `.enableAutoModifiers()`
+#### `.disableAutoModifiers()`
+#### `.toggleAutoModifiers()`
 
-### `.enableStickabilityForModifiers()`
-### `.enableStickabilityForLayers()`
+> Enables/disables/toggles auto-oneshot functionality for modifier
+> keys. When enabled, all normal modifier keys, including those with
+> other modifier flags added to them (e.g. `LSHIFT(Key_LeftAlt)`,
+> `Key_Meh`) will be automatically treated as one-shot keys, in
+> addition to dedicated ones like `OSM(LeftGui)`.
 
-> Enables stickability for all modifiers and layers, respectively. These are
-> convenience methods for cases where one wants to enable stickability for a
-> group of one-shot keys.
+#### `.enableAutoLayers()`
+#### `.disableAutoLayers()`
+#### `.toggleAutoLayers()`
 
-### `.disableStickability(key...)`
+> Enables/disables/toggles auto-oneshot functionality for layer shift
+> keys (see above).
 
-> Disables stickability for all keys listed. The keys should all be OneShot keys,
-> as if specified on the keymap. For example:
->   `OneShot.disableStickability(OSM(LeftShift), OSL(1))`.
->
-> By default, all oneshot keys are stickable.
+#### `.enableAutoOneShot()`
+#### `.disableAutoOneShot()`
+#### `.toggleAutoOneShot()`
+
+> Enables/disables/toggles auto-oneshot functionality for all
+> modifiers and layer shift keys.
+
+### Test methods
+
+#### `.isActive(key_addr)`
+
+> Returns `true` if the key at `key_addr` is in an active one-shot
+> state. Note that if a key is still being held, but will be not
+> remain active after it is released, it is not considered to be in a
+> one-shot state, even if it had been earlier.
+
+#### `.isTemporary(key_addr)`
+
+> Returns `true` if the key at `key_addr` is in a temporary one-shot
+> state. Such a key will eventually time out or get deactivated by a
+> subsequent key press.
+
+#### `.isSticky(key_addr)`
+
+> Returns `true` if the key at `key_addr` is in a permanent one-shot
+> state. Such a key will not be deactivated by subsequent keypresses,
+> nor will it time out. It will only be deactivated by pressing it one
+> more time, or by being cancelled by the `cancel()` method (see
+> below).
+
+#### `.isActive()`
+
+> Returns `true` if there are any active one-shot keys. Note: it
+> returns `false` if there are no currently active one-shot keys, but
+> there are keys that were at one time in a one-shot state, but are
+> still being held after that state has been cancelled.
+
+#### `.isSticky()`
+
+> Returns `true` if there are any sticky one-shot keys.
+
+#### `.isStickable(key)`
+
+> Returns `true` if a key of the specified value can be made sticky by
+> double-tapping.
+
+#### `.isModifier(key)`
+
+> Returns `true` if the specified key is a modifier key. This does not
+> include OneShot modifiers (e.g. `OSM(LeftShift)`), but it does
+> include modifiers with additional modifier flags (e.g. `Key_Meh`,
+> `LCTRL(Key_RightGui)`).
+
+#### `.isLayerShift(key)`
+
+> Returns `true` if the specified key is a layer-shift key
+> (e.g. `ShiftToLayer(2)`). OneShot layer keys (e.g. `OSL(5)` are not
+> included).
+
+#### `.isOneShotKey(key)`
+
+> Returns `true` if the specified key is a OneShot modifier or
+> layer-shift key (e.g. `OSM(LeftAlt)`, `OSL(3)`).
+
+### Other methods
+
+#### `.cancel([with_stickies])`
+
+> Immediately deactivates the one-shot status of any _temporary_
+> one-shot keys. Any keys still being physically held will continue to
+> function as normal modifier/layer-shift keys.
+> 
+> If `with_stickies` is `true` (the default is `false`), _sticky_
+> one-shot keys will also be deactivated, in the same way.
+
+### Deprecated methods
+
+The following methods have been deprecated, and should no longer be
+used, if possible. These functions made more sense when OneShot was
+based on `Key` values; it has since be rewritten to be based on
+`KeyAddr` values.
+
+#### `.inject(key, key_state)`
+
+> Finds an idle key on the keyboard, and turns it into a one-shot
+> key. When OneShot was based on `Key` values, this made more sense,
+> as it didn't need a valid `KeyAddr` to work. Since the main purpose
+> of this method was to enable the triggering of multiple one-shot
+> modifiers with a single key, it is much better to use automatic
+> one-shot modifiers, if possible, because then it's not necessary to
+> use a Macro to configure.
+
+#### `.isModifierActive(key)`
+
+> Returns `true` if a keymap cache entry with the current value of
+> `key` is active (one-shot, sticky, or held). This should be a
+> function that is not specific to OneShot.
+
+#### `.isActive(key)`
+
+> Returns `true` if a keymap cache entry with the current value of
+> `key` is in an active one-shot state. Please use
+> `.isActive(key_addr)` instead.
+
+#### `.isSticky(key)`
+
+> Returns `true` if a keymap cache entry with the current value of
+> `key` is in a sticky one-shot state. Please use
+> `.isSticky(key_addr)` instead.
 
-### `.disableStickabilityForModifiers()`
-### `.disableStickabilityForLayers()`
+#### `.isPressed()`
 
-> Disables stickability for all modifiers and layers, respectively. These are
-> convenience methods for cases where one wants to disable stickability for a
-> group of one-shot keys.
+> Returns `false`. OneShot doesn't need to keep track of whether or
+> not a one-shot key is still pressed any more. This function was
+> mainly used by LED-ActiveModColor, which no longer needs it.
 
-## Plugin properties
+## Plugin properties **[DEPRECATED]**
 
-Along with the methods listed above, the `OneShot` object has the following
-properties too:
+Along with the methods listed above, the `OneShot` object has the
+following properties, too. [Note: these have all been deprecated,
+please use the `.set*Timeout()` methods above instead.]
 
 ### `.time_out`