Other apps, including the foss AnySoftKeyboard, solve this by letting the user tweak the length of the vibration.
I am enjoying learning how to use the thumb-key:https://github.com/dessalines/thumb-keyI see a lot of potential in it. I miss the escape, control, and the alt keys, and a partial select (in addition or instead of the 'select all') would be nice. However, for all the bread and butter typing, it seems great to me now.
Premium will eventually show ads too.