Note that the diagnosis is without reading the code, it may be wrong (he says for CYA purposes :-).
Add-ons plugin contains a number of contributed bits that are too small to justify the overhead of a standalone plugin, thats why its called "add ons". Not all the contributors continue to check if their contribution has bug reports, so if you wait for a bit and nobody acknowledges they are looking into it, then probably best if you do it yourself.
Pull requests are preferred since thats the project workflow, a patch would need to be made into a PR which is more effort and would make it less likely to get merged in a project limited by volunteer time available.