You could cross your arms!!!
I am pretty sure you can set your board up to do this...with some limitations...
I can set up my Roland to do this..but, I would just cross my arms..
BTW. why not set up in full keyboard[piano mode], when you play three or more notes , it will change the chord recognition, and as long as you do not play 3 or more note chords ...you can solo all you want with in the chord...with either hand..
You may also be able to use a pedal when you want the chord recognition to change...the rest of the time[depressed pedal] you can play all you want without changing the chord recognition..