I think it would be very useful to provide a Capo feature. The effect would be to visually see the Chords and notes in one key while simultaneously hearing them in a different key.
Example: I play guitalele (tuned +5 semitones higher than guitar,) but I think of it and play it as standard tuning in guitar, yet hear it in the notes of the guitalele.
It could be used for a tune where the guitar has been Capoed(?), as well.
This could be used also for solos with transposing instruments.
I know I’ve used too many words to describe a simple function, but I hope you understand the intended request.