I hate clicking and searching through the signals UI a thousand times to find the item that I have to set in machines / combinators.
That's why I made a mod for it.

This mod creates a floating window that can hold up to 10 signals.
It can be toggled on and off through the shortcut bar and moved wherever you want.
You can then quickly select the signal that you need with the pipette tool (default is Q)

Mod compatibility

Since I just use the default signal selection UI, it should be compatible with all mods