> but a half dozen of these sort sorts of massive PR’s per week is basically untenable.

Actually, rejecting them is precisely what will make them easy.

"Sorry, the comments are so bad I'm stopping here. Please fix them and then I'll resume the code review."

You're giving everybody (including yourself) more work by:

1. Reviewing the code (even if you skip the documentation).

2. Letting too many abstruse comments in which everyone in the team will have to read.

3. Allowing the behavior to continue.

Become the bottleneck so the team can talk about it. If they decide this shouldn't be a blocker, just declare you won't review the comments going forward.

I think you’re overestimating how easy it is to just declare I won’t be doing my job.