I tried to add a scale factor of 0.85 as default for my plugin, so when opening it in the DAW it will initially show the GUI scaled to 85% (setGlobalScaleFactor(0.85)). VST3 and AU are working fine, but VST2 crashes when trying to resize the window. Once the scale factor is set back to 1, VST2 has no problems anymore.
I tried it with an empty plugin as well and I got the same behaviour. (on Mac 10.15.7)
The debugger shows that it crashes in the VST2 Wrapper resizeHostWindow function.