@jtbayly - I believe things may have started on the wrong foot here. The first sentence in your first post appears to put the blame on Discourse (the company), and that the issue is financial related (for the cost of our hosting). It’s hard to be friendly when the first post is accusatory.
There are details in previous topics about the Mobile App, but in short a decision was made to use the native push notification system for both major mobile operating systems. Both systems require that each site allowed to send a push notification be registered, which we do for the sites that we host. It’s not technically feasible to support every self-hosted site out there, as we don’t know all the URLs.
As per What if I want to white-label the Discourse Mobile apps? you can modify the open source app to suit your community. David shared a number of options that work as well, including the OneSignal push notification service. If you have an Apple iOS developer license it should also be possible to hook into Apple’s native push notification service too.