All of the places I have the Obi's are either at my locations, or family locations where people are computer illiterate, and would not know how to reconfigure anything - except my daughters.
One thing I thought of I occasionally use a 3cx softphone, and its been awhile since I set it up but I think it uses the PC app phone #.
How would the 3cx app work, if you tried to use that OBI PC app phone # on more than one computer?
also when I do call my daughters OBI (Obi to Obi **9-300-xxx-xxx) which is currently on a separate Obitalk account, I get a msg saying the number was rejected by the service provider