We too have had to do the workaround mentioned in this thread for multiple extensions. While the prefix works, the limitations mentioned are cumbersome and users grudgingly have accepted the solution for now.
Having the ability to register multiple extensions is an extremely desirable feature.
The stack Sangoma uses on Mobile does not support this. We both use the same stack and itβs not a feature of the stack. They only allow a single extension to register. I even opened a request with the manufacture of the SDK we both use a few weeks ago again and they have no plans on supporting this anytime in the foreseeable future.