Jittery / Stuttery / weird behavior with roto tool selected / roto brush effect applied

With the new "smooth" magnification introduced it completely breaks when switching to the layer window, and the roto brush tool is either just selected and or the roto brush effect is applied.

Also, magnification is not smooth on Windows

Steps to reproduce:
Select roto brush => click on footage to go into the layer => scroll with mouse.
And it's even worse when you start drawing on the layer to roto.. Magnification is completely glitchy / jittery / stuttery

Switching from Smooth to legacy kinda makes things better, but magnification takes a whole second to update..