What counts as a significant edit on Meta?

Some changes count only when they are large. Meta says a change to the ad set spending limit amount, the bid control, cost per result goal or ROAS goal amount, or the budget amount may or may not be significant, depending on the magnitude of the change. Its example: increasing a budget from USD 100 to USD 101 isn't likely to cause one or more ad sets to re-enter the learning phase, while changing it from USD 100 to USD 1,000 may.

With Advantage+ campaign budget, Meta says switching your campaign bid strategy might cause multiple ad sets within the campaign to re-enter the learning phase, and so might adjusting your campaign budget. It also says that, with Advantage+ campaign budget, a significant edit made to one ad set does not send the campaign's other ad sets back into learning. And it counts changing the disclaimer you place on an ad about social issues, elections or politics as a significant edit.

Meta times its exit from learning from the same point: it says ad sets usually leave the learning phase after about 50 results in the week after the ad set's last significant edit. It follows, and this is our inference rather than Meta's wording, that an ad set edited significantly every few days may never be given the week it needs.