I think the thing is flawed and goes again common thought process of what a RPS is. An RPS should be able to boot a device.
I watched the vid a few days ago and keep thinking about this. I’m with @David, granted one part of redundant is to keep the system running if one psu fails but this just seems like they are trying to re-invent the wheel. Sometimes that goes well but… sometimes it doesn’t.
If all the unifi kit had two of the 24pin connectors and you purchased two RPS’ and didn’t use a C13 then it would make sense (it would still be crap because you would NEED to buy at least one to be able to power your kit)
Just make a modular, hot swap-able power supply and put two trays in the back of everything…