Finally got round to running my plug for a reasonable time yesterday (had it since autumn) and was surprised at how hot it got .
Did a bith of math using the basic 10 W per sq metre fro 1 deg C temp rise that has serve3d me well over a career in electronics and figured from the 20 - 25 temp rise that there must be over 5W dissipation in the box and that air temp inside it must be another 20 deg or so higher.
Ambient of 70 to 80 C is pushing it for commercial components and will always lead to high failure rates - electronics are like us in the ambient temp they like ;-)
So i opened my box and found it was neat construction but with the PSU in that little box my estaimate of ambient for its components is very conservative.
I have no problems with little fingers getting at my kit - the kids are in their 30s so I drilled a matix of 6mm holes on top and bottm of case. It spoils the looks but so far its keeping everything cooler.
I think the Plug is a neat piece of kit and looks like a lot of thought has gone into it but my feeling is it needs more cooling or failures of stressed components esp in PSU are inevitable - A few fins on the case maybe? or a few more holes (not necessarily the colander I have made)
for the record had it > 3 months but so far run it 3 times on 240 V with USB hub and USB stick as well as SD card