Wheel and tire width are usually dictated by the weight they have to bear. Our XX has a lot of accessories, and carries a lot of weight over the rear axle (spare tire, winch, rack, etc). With a full load of fuel, driver and passenger we have 1062 lbs on the front axle and 1533 on the rear axle. My knee-jerk reaction is that you wouldn't benefit enough from 10's to deal with any fitment issues and the huge increase in scrub radius.
+1 to what Hollywood posted. I'm curious as to before and after impressions.
If the XX steering effort could be tuned like many of today's cars, I would opt for a little less boost. Those wheels should accomplish that, but also add a whole lot of kick-back on anything other than an ultra smooth or soft surface (like sand).