I just completed installing 7 Faikin adapters. I bit off a bit more than I could chew by making the wiring myself. I’d never used a crimper before, but got the hand of it by the end.
All flawlessly integrated with HA and no drop outs. They just work. A bit of latency but that may be due to my network setup or HA, it seems like latency grew as more units added.
Regarding power demand, I don’t see that feature but a screenshot in this thread does show demand settings, so maybe it is device specific and indeed supported. The dev is very reachable and I am sure he can answer any questions promptly over on GitHub.