I mounted my Vive’nChill fans, which worked fine on my 5K+, on my 8K+ connected to a USB socket.
When switched on the fans worked but unfortunately the headset didn’t or rather it lost tracking or disconnected and had to be rebooted, sometimes in the middle of a game, so look out with anything that is connected to a USB socket.
This is now known to Pimax who suggest that I use an external power source.
AFAIK the Vive’nChill fans draw too much power and/or introduce too much electrical noise into the line, which causes noise in the audio lines and apparently also causes tracking issues.
I didn’t realize that the 4K screens would make a difference in USB power supply but no problem as I still have a TPCAST and to use it I had mounted the battery on my DAS with a special 3D printed mounting piece. I have installed the DAS on my 8K+ so I mounted a battery in the same way.