macos-compose

These work in both X and Wayland, even though they are an X feature. X/Wayland will consult the standard file, but will also consult a file ~/.XCompose. A number of people have created files with extended compose sequences, of which https://github.com/kragen/xcompose is possibly the best-known. If you install or change ~/.XCompose, you must restart your session (log out and back in again) for it to be recognized. I used to bind the Compose key to Caps Lock, but I've recently decided that Right Alt is a better choice. Another commenter mentioned WinCompose, which I have used very successfully with Windows 11. On a Mac, you might try https://github.com/Granitosaurus/macos-compose, which is quite usable, provided you install Karabiner Elements for the remapping.

This. Using a Compose key [0] covers a vast range of input use cases and is eminently customizable. For Windows there is WinCompose [1]. For macOS there is [2]. [0] https://en.wikipedia.org/wiki/Compose_key [1] https://github.com/SamHocevar/wincompose [2] https://github.com/Granitosaurus/macos-compose