Sorry that this is not getting much response. I know it’s frustrating!
I think probably your best bet is to find out who’s a maintainer of that package, or who has knowledge of its internals, and try to approach them on Matrix chat. GNOME developers do have merge permissions for any package, but along with that goes that people are generally cautious about using their powers on packages that they’re not familiar with. This looks like a nontrivial enough patch in a package that I’m not familiar with, that I wouldn’t be comfortable just going ahead and merging it, and I suspect others might feel the same.