Each room has a 4 button Hue Zigbee button: Ceiling lights on/off, brightness up, brightness down, then the Hue button turns on/off bedside lights, floor lamps etc.
The three iPads are all in different places: main entrance way/downstairs hallway, top of the stairs/upstairs hallway, in the walk in closet of the master bedroom.
Each iPad has a default screen with the lights in the area around it, while also able to change to other views in HA so control heating, robot vacuums etc.
We have 3 of them, mounted to the wall, for home automation stuff. Each room has a Zigbee button at the doorway etc, and then an iPad in the hallways etc for more fine control via Home Assistant.
If you feel that your equipment is that questionable that it could catch fire at any moment, it’s time to replace your hardware.
Grab a can of compressed air and blow everything out once a year to reduce the risk of combustion. If you’re worried about things shorting out: do you have some questionable sata power splitters that need to be replaced? Anything like that you’ll replace all of them for $50, so just do it for peace of mind.
Don’t use the cheapest worst power supplies, use something that’s been reviewed and known to have working over-current protection which will cut the power should something go wrong.
And, as a last resort, find some kind of smart smoke sectors (or way to monitor audio/broadcast from smoke detectors) and a trust worthy smart power plug (with power monitoring) that you can connect all your gear to, so you can set up some automation to tell you if the alarm goes off, and either turn off the power automatically or have a way to remotely turn off the smart plug.
The smoke alarms we have, are 4 that communicate wirelessly between them, so they all go off together. Let Home Assistant monitor for that freq and you know if any smoke alarms go off.
Adding to this, I’m assuming the PSU is around 1000watts, and there’s two of them. Operating a power supply at lower loads reduces the efficiency, having two would decrease the load more, making them less efficient. That missing 40 watts is 20 watts per PSU, which seems acceptable.