Sadly I don't have a specific proposal to offer but I do want to say that almost any method I could imagine of addressing this problem would be better than the status quo, IMO. Among the communities I'm watching, the Mathematics community in particular has been utterly overwhelmed by a flood of low-quality posts that still skate above the line currently used by moderators for closing. I would strongly endorse a plan of getting some flood control out quickly and refining it later over one of debating at length over the ideal design.

This definitely sounds like something that needs to be brought up at the specific community meta. Preferably along the lines of "how can we improve post quality?" which is productive, and not along the lines of "user x is bad what can be done about them" which is counter-productive and quite rude.

I agree with Lundin‭ that publicly singling out specific users for inappropriate behavior is rude. Generally, doing so only puts those people on the defensive, often destroying any hope of getting them to improve their behavior while remaining contributors. That's why what I propose focuses on the problematic behavior itself, not who is doing it. There are, of course, some users that I have in mind — I certainly don't propose this functionality just for the fun of doing so — and I'm sure others who are even moderately active across Codidact will know of some particularly problematic users that they have encountered as well. However, at least I refuse to publicly name and shame them; I'm not doing this out of spite, and I'm not doing this to target specific users, but to target an inappropriate behavior; if a problematic user improves, I'll probably be among the first to applaud that, but in the meantime, I think we need some way to keep communities from being drowned in crap.