From a local TT race rule book:
"To establish a Personal Record (PR), a rider must have completed a total of 5 events with at least 3 events during the current series. A rider that has no race history will be eligible for a PR when he/she finishes at least 5 events in the current series. A PR medal will be available for eligible riders that established a new PR on the last event of the series."
I think it would be great for anything really. 5k's, TT, shoot......even IM or something. Minimum of 3 prior events within 3 prior years for long course. Or 3 5k's or TT's per season.
I think things like that kind of quiets the whole "ringers" argument about AG racing. You'd still have an award to chase independently.
It kind of bridges a gap between folks competing for the win and those getting just another finish medal.
I'd rather get one personal best medal instead of three separate finisher medals for an event.