I also have a project called dedaemon: https://github.com/mortie/dedaemon. That uses udev to listen to events, like displays or input devices being connected or disconnected, and does a preconfigured to them. I for example have these lines, which sets the resolution and frame rate to any connected monitor to the highest possible, and positions it to the left of the primary monitor: https://github.com/mortie/nixConf/blob/7c12d4215c703de0c6935.... I imagine porting that functionality to wayland would be really hard, and probalby require writing custom extensions to each window manager separately.
There's also this other project I have, which isn't really related to wayland, but which I still feel is relevant: mmenu - https://github.com/mortie/mmenu. It just makes dmenu work as a calculator, running the input through python if it doesn't match a program in your $PATH, plus some other features.