@strypey I don't think GitLab has plugin support, to my knowledge, so it would have to be a patchset, with the obvious usal problem of having to fix breakages happening because upstream doesn't know the code exists, and the other usual problem of explaining to users how to patch their vanilla GitLab, or having to distribute a patched version.
**But** it's still an idea worth considering, I think, in retrospect. 😅 Because it would allow to bypass completely the major pain point of contributing to GitLab: being forced to send very small MR, just a few lines at a time, and having to explain again and again to new people reviewing it what the whole point is about and how you're doing it, which causes each small MR to take weeks to merge, and then you have 4 or 5 more to merge because you had to split your feature. For something like ActivityPub that is made of many features, being able to develop the support independantly without this grind would certainly help.