there is always a potential heat problem stacking on top of amplifiers,but i'm not familiar with the 7100.is in vented on top,sides,heatsinks on the rear,cooling fan?
always a possibility you could put a personal fan behind it,out of site if you had to stack.
i see some people stack 200's so maybe outlaw has it figured out nowadays but my 1050 runs on the warm side just powering surrounds and it's on it's own shelf with alot of ventilation