Using Kubuntu 20.05 / KDE Plasma 5.18.4.

Is there a way to create a custom shortcut for Ctrl+Alt keys (only)? In the UI, it seems to require a non-modifier to be pressed, or it won't register (this was easy to do in Mint/Cinnamon, which did pickup & register the Ctrl+Alt keypress in the UI & bind it to the selected action). I did find some instructions on modifier-only hotkeys (i.e. https://forum.manjaro.org/t/howto-use-modifieronlyshortcuts-on-kde/67650), but they seem to only work for a *single* modifier (i.e. Super key, or Control key, or Shift key - I couldn't figure out how to do a two-modifier shortcut).

Any pointers would be greatly appreciated.

....Or if this is not the proper place to ask this & get a reply, perhaps there's a better alternative...?

If you didn't get an answer I presume nobody has one, and it is very likely you can't do this on Plasma.

Was about to post a bug on the tracker; looks like it's something many people have kept reporting over the years, but the devs insist on not allowing people to have their desired behavior. i.e. https://bugs.kde.org/show_bug.cgi?id=59027.

Bummer. I never even considered it wouldn't be possible, as this is the first time I've ever seen such a scenario - works fine in Windows, AHK, Cinnamon, etc, & I always thought KDE was the *most* flexible