okay i uploaded two -gles2.zip files for win and mac - see if those work for you?
just had to convert a couple particle systems, no biggie
Ah the log path helped, thanks. In case other people read this, I had to disable my integrated graphics card: https://nvidia.custhelp.com/app/answers/detail/a_id/5182/~/unable-to-launch-vulk...
If you're doing the signature region using Unity UI, you can have it so that the signature hitbox blocks raycasts by adding a Canvas Group component to it. This will make it so that whenever Unity detects that you're hovering over the signature region, it blocks it from also detecting that you're hovering over the paper object behind it.
On each signature there's an invisible rectangular region that tracks whether the mouse is hovering over it. With Unity UI you can do this out of the box with an Event Trigger component. In the code there is a check that only adds points to the signature if the rectangle is currently detecting a mouse hover.