Could you add a note cut tool + a shortcut button to quickly switch to it? I think it can be handy for quick editing. In PiaPro Studio, the program tries to best-separate the phonemes between the two notes, but I think just giving both notes the same exact word+phonemes could be fast to work with, too.
EDIT: If we could temporarily use the pencil tool if we held down CTRL/Command while using the selection tool (and vice versa), that could allow for even faster editing. Can we consider this feature too? I really like using that shortcut while placing notes in FL Studio’s piano roll