Well... I have [xiota/geany-tweaks](https://github.com/xiota/geany-tweaks), which is basically just anything that I think doesn't fit in [xiota/geany-preview](https://github.com/xiota/geany-preview). I've opened PRs for Geany when I think features fit better within Geany, aren't really possible to do in a plugin (#2899, #2919, #2949, #2951, #2952, #2953, #2955, #2974), or address open issues (#2956, #2972, #2973).
This one, and another one that I have in mind, can be done in a plugin though.