When pasting a series of notes, I wish two things wouldn't happen:

1. Pasting duplicate notes over existing notes. If there are duplicates, then ask me whether to a) keep the original, b) replace it with the new, or c) keep both (which would be rare). Alternatively, always do either (a) or (b), that would be fine.

2. Pasting connections to notes that aren't being copied. When I paste a partial chord shape with a few connection lines, I don't want connectors to reach back to the notes I didn't copy. I only want connections within the notes I've copied. This is especially true when pasting into a different fretboard: I don't want connections reaching back to the source chord in a different fretboard.