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?
Xremap, despite the name, supports both X and Wayland, and can be used to move modifier keys around. Configuration is done with YAML but is otherwise pretty easy. I personally use it for full Emacs keybind emulation.