feature-request: Border around borderless windows

The title might sound strange, but use case: Turn off window decorations in options. Have terminal over one another or over other windows of similar colour it can sometimes be hard to distinguish.

Something like:

MiscColorBorderWindow=rgba(100, 100, 100, .4)

I use this "mode" most of the time as to get rid of title-bar etc. So no scrollbar, no title-bar.

Such a border would of course work just as well on a Bordered window with title-bar.

Below are some shots to explain.

Current:

With Subtle borders:

Stronger borders: