Let us just allow it!
Equating LLM generated code to "lab-grown diamonds" is disingenuous at best.
> Someone would be happy to take them and [be] none the wiser.
If the quality of GenAI PRs were equivalent to those authored by experienced contributors, then there would not be as many GenAI PR bans in FOSS operating system repositories.
If it "looks like claude" in that it's overly verbose (in code or comments), missing tests, etc then it should be rejected for lack of merits. If the only indication is "this user fixed 10 bugs in an hour" and the PRs are otherwise fine on the merits, rejecting the PRs because an LLM wrote them is the same as rejecting them because you know they're from an emacs user.
You don't know that they are low effort PRs until you expend time and energy, while in the meantime more important PRs might be in the queue that can potentially never get seen if the submitter decides to keep that rate up for a week.
The project will die before you get to other's PRs decades later.
The answer might be to RR reviews from submitters and not treat PRs as first come first served.
That way other submitters don't have their PRs blocked.
Why? Because the onus of determining fitness of purpose and correctness has to be done by someone. So if a PR is buggy and/or lacking in test coverage, but was made by a contributor making an honest effort, then experienced contributors can help educate the person as to what is missing or needs to be considered. Ultimately, this is a form of apprenticeship.
Contrast that with someone using an LLM to produce the exact same PR. Who can be mentored? Who can be referred to materials which can deepen requisite knowledge?