Wow, great answer, didn’t think about using the compose key for this. And even more, it would be kind of easy to make a GUI interface to set up this kind of shortcuts for non technical users.
I think it would be awesome if Fedora got up to speed with macOS in this feature, but I also think that this should be doable tinkering with input methods as you said. If anyone knows of a project that is experimenting in this direction, I would love to know about it.
Text substitution in macOS goes further in that it doesn’t need you to know about the compose key and that it even autocorrects common typos, and power users coming from those lands would greatly appreciate a similarly easy to use and configure solution.
Thanks for your help!