Hello Nick,

I don't have the Motif XS, but I think only few are sending midi data, without interacting internally too.

Any vArranger function can be controlled by any midi message. The only thing to be careful, is that this button does not change things inside your XS together. Maybe there is a master keyboard mode, where buttons and sliders sends midi data, but does not change the internal sound.

I think the big buttons like REC PLAY .... will work, as well as the sliders


If not, you can simply add a cheap Korg NanoKontrol2

https://www.youtube.com/watch?v=otV1oLeaLRE