what's proper way to shut down since there is no power button?
Remove the Ethernet cable until the fans stop spinning then power down the PSU.
Where is the advance instead of just turn off the PSU?
It is not turbodiesel with turbine to cool off

+1. You can turn them off hot, its not like they will get hotter or anything.
however, i usually just unplug the ethernet, let it start beeping and wait a minute while the fan continues to cool down the heatsink a bit further. This is a bit overcool, and mostly if i am moving the miner to a box or handling it in a way that it being 40C is not desirable
I do not need to turn off. It heats four of my rooms + a bathroom + stairs. LOL