50C exhaust temps are fine though, as long as the intake temp is below 40C. PSU components aren't so sensitive like a CPU or GPU. The ST30SF only even switches its fan on at 55C internal temp. Will probably be similar with the SX600-G.
Well i hope so because i've had my PSU shut it self down from overheating, 50C is the temp of the top panel i should read the temp inside the unit i mite run a sensor inside it.