Interesting this patch persist, as it appears it can hold the notes of the old sound but leaves the notes of the new sound to play separately, as while current instruments maintain the sound of the previous patch (Such as sustain on strings) rather chopping it off when a new sound is selected, also if you press the sustain pedal it will hold the previous patches sounds, and the new patches sound as well. (It’s such a simple thing, it makes you wonder why no one thought of it before as the current system came out in the 80s)
Bill