I think that WBQC could be very helpful in battling vandalism and accidentally incorrect edits if integrated into the recent changes and the watchlist, similar to ORES. Any edit that adds constraint violations (or, for a simpler first version: that increases the number of violations) could be highlighted.

On the technical side, I imagine that this would require support for specifying revision IDs in the wbcheckconstraints API, and then the user script / gadget would just get violations for the two revisions and compare them (or their count). (This would not be a full history of “what constraint violations existed at this point in time”, since all referenced entities would still be checked in their current version; the API documentation should make that clear.)