Ah-ha - the penny dropped, I think. Are you referring to the
Find Duplicates->Find metadata variations... option?
For no obvious reason I've never used that feature (maybe I should). And yours is the first thread I can recall that's ever referred to it - albeit somewhat obliquely
Tip : when referring to calibre features please try to use the precise words as they appear in the user interface. Or post screen shots.
If you want to make a request for calibre itself to be enhanced then this is where you can do that ==>>
Bugs : calibre
If you want the
Find Duplicates->Find metadata variations... option to be enhanced to include a history of prior replacements then make a post in the FD thread in the Plugins subforum. But you should be aware that the author of the FD PI is currently inactive and has been for some considerable time.
If you think it could be done via a separate PI, there's a sticky 'Plugin ideas' thread at the top of the Plugin's subforum where you could make a request.
Or you could write your own PI or hack the existing FD PI.
BR