Search the History for a Tag

Does anyone know how to find if a ticket was ever tagged with a particular tag?

I want to enjoy the feature where a ticket can be tagged as Priority for support purposes.  When complete, I want the tag to be removed (this action already works).  Finally, I want Priority-tagged tickets to be reportable i.e. be able to count tickets that used to be tagged as Priority but are now complete.

Alternatively, perhaps it would work if ticket completion could remove the Priority tag AND add another tag e.g. "PriorityComplete" or "WasPriority".

I saw an old question about this from 2012, where the given answer was along the lines of "the data doesn't exist".  I've only been using YouTrack since 2014, and I know the History does exist, because I regularly find myself laboriously reading it.