I had thought about this option, but what makes it really difficult is the consistency between drumtracks and chord tracks. I´ve spent a lot of time to provide making every track switchable between one or the other so now every track can be drum or chords/notes. But exchanging patterns between drum and chord tracks would result in garbage, as they handle certain memory regions differently to each other.
Also, I then thought it wouldn´t make too much sense anyway, because even inbetween synths, ususally you don´t assign a different instrument (track) the melody that another instrument was just playing?
All in all I had then decided against adding that option…