that's an excellent idea....tho the drum ones might not sound anywhere near as good with the (rather tepid in my opinion) tyros drums.
I hope those arps give a clue about future yamaha arrangers...very creative way to work, and the control over tone and effects(w/ the XS knobs, etc) is just great.
I no longer have a T2 and only briefly worked w/ an XS, but I do wish I'd experimented w/ that...pls let us know if you get it going...