Thanks Matt, I think that's right. Although the guitar macros pull down menu doesn't seem to need the pattern rendered as just a rhythm, with all the notes on the same pitch. So maybe that idea could work for a voicing table.

As I said it's a function as old as midi editing itself in all likelihood. For example, BIAB style editor already has a global velocity adjust parameter for user specified notes that target individual patterns, a whole row of patterns or the entire instrument. It's just a matter of turning that idea into moving the chosen note with a user-friendly interface.
Considering BIAB has the 'fix sour note' command in the mixer window track settings dialogue it's already doing a kind of intelligent pitch alteration according to a selected scale. So, in theory, it shouldn't be a big task.

btw, the program that had this capability I couldn't remember earlier was Jammer Pro.

Best wishes

Alan