Is your feature request related to a problem? Please describe.
During work on Keyman 12.0 in support of predictive text, I wrote the dom.uiTouchHandlerBase class for use by the suggestion banner. Its design is a direct abstraction of the OSK's touch handling.

The intent was always to, at some point, swap out the VisualKeyboard's code to subclass from this abstract base. We just haven't done that yet... in part because the OSK has yet to be fully refactored / converted in the same manner that has been done for the rest of the KMW codebase.

This is probably best done whenever we decide to target other aspects of the OSK's technical debt as well.