@kugiigi mind sharing that PR link?

I'm also used to this (even though I much prefer proper physical keyboard phones and hope there'll be some more in the future), so for inspiration, here's an open source "gesture typing" implementation that works quite well:

https://github.com/AnySoftKeyboard/AnySoftKeyboard/blame/a3ee809ebf7c2ea3fd72138a862854089b595aa5/ime/app/src/main/java/com/anysoftkeyboard/gesturetyping/GestureTypingDetector.java