I took a deep dive on this and have got it working. I don’t see any
obvious issues in this patched version but I’m certain there are edge
cases I haven’t tested.

I haven’t tried modifying cursor colors or fringes or even diverse
face backgrounds (I’ve only been working with default face), but this works for MacOS users.

Only open question I have to look into:
- The alpha on the ns transparent titlebar is off. I need to determine exactly where I set that.


Cheers,

-- 
Jon Rubens