Everything I read says it’s a feature enabled in what ever compositor you choose, if your compositor supports it. Why isn’t there a general purpose keybinding program like setxkbmap? Does it just not exist yet or must it be built into the compositor?
I’ve read [this stackexchange thread] on something related but it all seems to be using XKB which should imply I’m using XWayland?
I use keyd to make capslock work as escape when pressed, and as meta when held. Though you could configure it to function as control when held too.