I’m not quite sure if this an error, but I’m in the key of D# minor and when I attempted to make an Amaj7sus4 chord (A, D, E, G#) it gives me a chord with A, D#, E, and G# instead. I’m not sure if this has some work around but, all I can say is that it isn’t the chord I’m looking for.
I’m assuming that you’ve gotten this Amaj7sus4 by borrowing V from the locrian mode? If so, then the key signature of D# Locrian has four sharps, so the 4th degree would be a D# not a D natural. If you’re interested in the D natural, you could always change your key (A major is already pretty distant from D# minor).
Alright, I wasn’t sure if there was any way I could implement the chord without having to change key. Maybe a feature you could add later on is borrowing from a different key instead of just borrowing from different modes.