Would help when learning cover tunes or playing along with prerecorded tracks. It would be a great learniong aid to be able to adjust the overall guitar pitch to match the track. I can't tell you how much this occurs, even with really well done tracks, the pitch can be off 20 - 30 cents easy. And it always changes from track to track which makes retuning extremely tedious.
Maybe a control applied at the input, this way it would not have to burn up a slot.
I think there might be others who would find this useful and if anyone knows a way to do this now, please share it. Thanks.