Good to hear, the only reason why I elaborated is a lot of people come here and expect to just be able to install some free SIP app off the store and push to work out of the box and think it's a problem with FusionPBX and they think there's some magic toggle you can enable.
Ah yeh, was going to comment there. Worth testing to make sure it doesn't block both 'Simultaneous' and 'Enterprise' ring groups too, one creates multiple threads and one uses a single thread, I could potentially see a delayed response from the API locking up the calls for the other phones that aren't push notified.