Oh, right. I knew I forgot something.

I use https://github.com/alols/xcape for some while now. It's old, reliable and straight forward, just does it's job. Only downside is that it seems to be limted to X11. Not sure how well it will play with wayland.

There are now also some alternative tools, with more ability, which allow overloading just on the side. I have them on my list for a while now, but not done much yet with them.

- https://github.com/david-janssen/kmonad

- https://github.com/mooz/xkeysnail

- https://github.com/snyball/Hawck

Oh, and for rermapping capslock there are also options with X11. I use

   setxkbmap -option ctrl:nocaps

to map ctrl to capslock, then overload it with

    xcape -e "Control_L=Escape;"

to add ESC ontop.