[lelandfe]

> these specific shortcuts were frozen and un-customizable

I think Karabiner should allow you to do this: https://karabiner-elements.pqrs.org/

It's a utility that "remaps" keys – you set up key/key combinations that fire the original key/key combinations (it does not remove the original combination). E.g. you could bind Cmd-Q to Caps Lock if you wanted a really fast way to quit stuff.

[JadeNB]

The memory of what happened with kext's always makes me leery of relying on anything that reaches too deeply into macOS's guts, so I've always shied away from Karabiner, probably unreasonably.

Old-style OS X believed in customisation—even now, you can set per-app keyboard shortcuts; it doesn't seem possible to bind Cmd-Q to Caps Lock, but, after slipping from Cmd-W to Cmd-Q and so quitting rather than closing a tab one too many times, I do have Cmd-Q bound to Cmd-Opt-Q for Safari only—and yet there's no Apple-blessed way of changing _those_ shortcuts, when it clearly had the architecture in place to allow it. That always irritated me.