Steven Degutis <sbdegutis@gmail.com> writes:

> It's now called `auto-dim-other-buffers` and it just got a whole lot more
> efficient and faster: https://github.com/sdegutis/auto-dim-other-buffers.el

I see that you introduced some intelligence for operating only on/when
the buffers affected by the change. Maybe it is worth to try the overlay
approach. I bet that it will be efficient enough.

What I'm concerned about is the collision of the overlay that auto-dim
creates with the overlays that might pre-exist in the window. But the
current implementation already suffers a similar problem with faces, so
it can't be worse.