I've been watching this project/issue with interest :) It is on my long todo list to dig into this. One of my worries is that even with a hardwired device, the doorbell transformer may not give enough juice for continuous video use. I notice that just after a few minutes of watching the live feed the health status reports 96% battery (down from 100%). Hopefully that isn't the case, and someone is able to find a way to pull the video feed without funneling it through ring.com's infrastructure (I'm sure they wouldn't appreciate a 24x7 video feed running through their systems :))

Well one "solution" could be to just grab "snapshots" of the camera once a second (if it responds fast enough) then close the connection.

I have a Ring "Pro" so the battery level isn't an issue and it's able to do live-view for a few hours no problem (I tried it by leaving the windows 10 app up and running on live view for a while).

Still, if it really is running SIP the whole way, then it most likely can be accessed locally without touching their infrastructure (unless they are using something custom for the Ring-Servers -> Doorbell connection...)