Feature request: Highlighting window that will be focused after releasing keybind

[ghost]

GNOME's "Switch windows directly" switcher (Alt-Esc by default) shows an inner border on the window that will end up being focused/raised until you release the modifier key. I would like something similar but I don't have the knowledge to know how to do this. Can you implement this feature into the extension or point me to a utility I could use in bash scripts to reproduce the effect?

[e3rd]

Hello, if I come across such functionality in the documentation, I might implement such useful feature, alas I'm not the one who knows the secrets of GNOME internals.

Unless some information given, I do not plan to put this on the roadmap now.