Aka. Press a hotkey > open a floating window of Image/UV editor. Press a different hotkey > open a window of Node Editor, etc…
Bonus: Press the same hotkey again, and it closes the window, aka. Press hotkey > open float of Image/UV editor, do some work, press same hotkey again and if the Image/UV editor is already open, close it. Press again, re-open, etc…
Thank you so much for any help (this was a standard in my beloved discontinued application and after a year with Blender, I still miss it). -Cheers