> his is absolutely the headache I’m having today, an enthusiastic contributor pasting AI generated wall-of-text comments to justify their 500 line PR.

Easily solved - call that contributor into a meeting to explain their PR. If they cannot explain it verbally, it would be made clear to them why it cannot be approved without you having to actually say anything.

In the good old days (SVN), code reviews at places I worked at were done by booking one of the many small rooms and throwing the diff up on a projector. The author could defend, explain, etc.

Maybe we'll have to return to that type of code review from now on.