i use the A4 to control an XS.

i have cv / gate in controled from A/B

and velocity and filter mod control from C/D. works a treat.

the only shortcoming i find on the A4’s part, is that you dont use the “velocity” knob from the note page to control velocity. in the cv track it appears to do nothing. instead you have to just send a dedicated control voltage paramater lock to control velocity. - it would be nice if there was a way to route the main velocity control to cv out… nice but not essential, as this would allow the ability to copy an A4 internal track to a cv track with more ease.

you are going to love the combination of XS + A4

edit. also should mention that setting is just my bread and butter setup. there is fun to be had with experimentation also.