Current rules do sort of cover this, though, at least for nominators:
BN Rules wrote:
At least 24 hours must pass between a first nomination and a qualification on every mapset, ignoring renominations for minor changes. This gives other Beatmap Nominators and also the wider community the chance to provide additional suggestions before qualification and veto the placed nomination if necessary.
The part "renominations for minor changes" only refers to nominations after the mapper made a change that caused BanchoBot to pop the map. Disqualifications and manual pops (any non-automatic response), however, are not part of this, which means nominators will
always need to wait 24 hours after those,
unless a member of the QAT says otherwise in the case of a disqualification (basically is about to instantly requalify the map, but can't without help of a nominator or other QAT, since modding v2 doesn't have that option).
Think of it like this: The 24 hour clock, that starts upon first nomination, is not stopped by self-pops, but are by dqs and manual pops, restarting the clock from 0.
Essentially what we were trying to do with this was mimic the way instant requalifications worked in modding v1. This way, just like in modding v1, the QAT determines whether the map is ready for nomination again and whether to instantly qualify it or leave a delay. This is done in the same way as the "renominations for minor changes" part works in the rule, except with additional guidelines more or less stating the same as what Gabe suggested above.
That means if the QAT determines the changes made to be minor according to those, they can instantly requalify, just like how a BN would determine whether the changes to a self-popped map were minor or not. Although, this is where the actual problem lies;
what does "minor changes" actually mean?
Just noting that the thread looks a bit misleading with the first post and title only referring to one but not the other, as this not only applies to instant qualifications after disqualifications (which is what's brought up here), but also qualifications without a 24 h delay after a self-pop, since they both work the same, only difference being when and by who.
That being said, I do think the suggestions brought by Gabe makes sense as a way to define this, and is how we've been doing it in the past. However, things like adding a few hitsounds or resnapping a 5 ms unsnapped slider end (which are technically gameplay changes), barely affect the map, and are things we normally wouldn't even disqualify for unless they were really noticeable, so forcing a 24 hour wait time for that doesn't make a lot of sense. It could even end up being detrimental in the long run, as too small changes may not even be considered worth pursuing, especially when it comes to the regular 24 hour rule, which is part of why it was changed.
tl;dr: defining what minor changes are is kinda tricky and I'm not sure if applying arbitrary rules on top of it to create a cut-off will actually be beneficial in this case. Having this as guidelines and keeping it case by case seems to make the most sense, at least from how I see it.