With the current implementation of T181060: Cache constraint check results per-entity in ObjectCache (L) (days: 2), cached constraint check results will be invalidated whenever the properties defining the constraints which were checked are edited in any way. However, we only really need to invalidate them when the constraint statements were edited, which is a lot rarer. From T182110: Only update constraints table when constraint statements were edited, we theoretically know which edits affected the constraint statements and which didn’t, but currently don’t keep track of that information.