Finished the driver and installed it. Saving for archive.

doc/behavior.md

@@ -19,14 +19,35 @@ surface-dial-renewed --mode wheel
 Normal Dial rotation emits a synthetic two-finger touchpad scroll through
 `Surface Dial Renewed Touchpad`.
 
-The driver starts a virtual two-finger contact on the first rotation event,
-moves both virtual fingers vertically, and ends the touch gesture after no
-rotation has arrived for 2 seconds.
+The driver starts a virtual two-finger contact on the first rotation event and
+moves both virtual fingers vertically. Gesture release is dynamic:
 
-The 2 second hold is intentional. Very slow physical Dial movement can emit
-sparse `REL_DIAL` events. If the virtual fingers are lifted too quickly, libinput
-can treat those sparse movements as many tiny gestures and ignore them. Holding
-the contact makes slow and precise movement accumulate into one gesture.
+- normal and fast rotation releases after about `100ms`
+- sparse precision movement can stretch release up to `1500ms`
+
+The `100ms` minimum matches the old driver's multitouch control. The timeout is
+based on the time gap between rotation events, not the raw delta size. That is
+important because the Dial can emit `delta=1` even during normal fast scrolling.
+If the virtual fingers are lifted too quickly during sparse movement, libinput
+can treat those sparse events as many tiny gestures and ignore them. If the hold
+is too long, page-edge overscroll animations can remain stretched for too long
+before bouncing back.
+
+The driver keeps the last rotation timestamp even after a virtual touch gesture
+ends. This matters because sparse precision events can arrive after the 100ms
+gesture has already been released. The next event still sees the previous event
+gap and can stretch the new gesture timeout. A gap of `2500ms` or more is
+treated as a real pause and resets back to the `100ms` minimum.
+
+Timing is configurable:
+
+```bash
+surface-dial-renewed --mt-idle-ms 100 --mt-idle-max-ms 1500 --mt-settle-ms 80
+```
+
+`--mt-idle-ms` controls the fast-scroll minimum release timeout.
+`--mt-idle-max-ms` controls the slow/precision maximum release timeout.
+`--mt-settle-ms` controls the short stationary frame before the fingers lift.
 
 ## Sensitivity Selector
 

doc/installation-service.md

@@ -52,6 +52,25 @@ The service runs:
 
 It restarts on failure with a 2 second delay.
 
+To tune multitouch timing in the service, edit:
+
+```text
+~/.config/systemd/user/surface-dial-renewed.service
+```
+
+Example:
+
+```text
+ExecStart=%h/.cargo/bin/surface-dial-renewed --mode multitouch --mt-idle-ms 100 --mt-idle-max-ms 1500 --mt-settle-ms 80
+```
+
+Then reload and restart:
+
+```bash
+systemctl --user daemon-reload
+systemctl --user restart surface-dial-renewed.service
+```
+
 Useful commands:
 
 ```bash