

The Nest ones? I haven’t seen anything online of folks successfully flashing one. The first steps would probably be to solder on a USBC port and see what kind of access you can get over serial. There’s a picture of a Nest board (not the Pro) here, as well as info on what appears to be the correct usb connector. The OP also mentions that the Nest is lacking the developer button, but my guess would be that the function is still accessible by shorting the correct TPs. It doesn’t seem like that OP ever went through with the project, though, so maybe you’ll be the first!

Why not both? My initial idea was to flash to NOR and then configure openwrt to a sort of “minimal usable state”. That is, I’d have the basic functions required run my home network: basic routing between local networks and WAN. Then I’d copy that image to NAND and that would be when I installed the “extras”, like SQM and whatnot. That way, if I ever broke it beyond repair, I could just flip the switches and copy the NOR back to NAND and start over with that minimal usable config.
I sort of followed my plan, but I think things have changed enough that it would not be the simple restart that I hoped it would.
I still think it’s a good idea, though.