Hi Dave,
if you come up with a better setting for piano on sx luv to know what it is. I just press the sustain button on mine for r/h melody, good enough for my playing skills .
Weird , I don’t like using the sustain pedal on the keyboard, but no hassle using it on the p121.

I did manage to hook up my p121 to sx900 via via USB cables using my laptop as an interface. Not ideal but just wanted to see how sx piano sounded played via the weighted keys. Gives a much nicer feel.

Still debating whether I just keep using them as 2 seperate instruments or go out and purchase a proper interface.