I sat down and played a couple PSX games today. CTR seemed to go okay, along with a short Gran Turismo stint. After about half a race in Colin McRae 2.0 though the Pi3 froze. So it looks like I am running hot with the enhanced resolution enabled.
Turned on my old PSU fan setup and everything was at 50 or under and no more freezing. I guess I wasn't testing PSX for long enough before when I thought it wasn't getting too hot.