Did you know that the XV responds to Polyphonic Aftertouch?
The whole synth responds to it.
So many manuals, so much missed information.

Anyway I have been having a bit of fun with a program I just wrote that converts the Channel Aftertouch to the last note played Key Aftertouch.
Chord in the left and solo with bends in the right hand.
A a variable amount of vibrato just in the solo part? Sure thing.
Lots of fun so I thought you might like to try. (PC program I'm afraid)

Modify the patch by putting setting Aftertouch (Key and Channel are grouped together) to Pitch in the Matrix for pitchbend or Aftertouch to LFO1 PCH DEPTH for variable vibrato.

http://www.bwalk.com.au/ChannelToKey/ChannelToKey.html

All the best
Royce