- If the data wires need to be disconnected, then that's too easy to do when splicing in a micro USB cable at the end of each run

- I had to back-burner this for several reasons Brian, but as for hardwiring the pucks, if you have decent access to the wiring inside the walls, I would just get the 24v power supply and buck converter...

- I can just use an adjustable buck converter to compensate for voltage drop where necessary.

- And yes, the fact that your vents allow for hardwiring is a huge plus. They definitely will be. There's too many batteries involved in home automation as it is.

- Yeah, I mistook that for a DC output box. One or two of these should do: https://www.pimfg.com/product-detail/PIDB-24VDC-9B

- All the low voltage wiring goes back to the mechanical room.
  
  Two 2.5A outputs of this: https://www.altronix.com/products/product.php?name=ALTV2416ULCBI3

- That is an interesting solution. I'm sure a lot of folks might like it. For me personally though, I'm wiring up some new construction with low voltage anyway, and I'll be mounting thermostats high...

- From "https://support.flair.co/hc/en-us/articles/360000522112-How-does-Flair-account-for-back-pressure-in-central-systems-":  
  "Not only do we use pressure sensors to understand changes to pressure,...

- I'd like to confirm that the puck is powered at 5 volts, please. A USB cable, in and of itself, does not necessarily imply 5 volts. Thank you