Thanks,
(1) it works but is quirky with manipulators using modifier keys (e.g. shift). I guess it a matter of coding more logic in the event handler.
(2) I noticed it with the official example and the docs above on firefox 89 on Ubuntu 18.04. It does not manifest itself in the three or twgl example. Should I maybe try adding a scroll event handler that forces rerender at the very beginning of the code?
Best,
Adam