I fear i did not understand anything from the above
so you have 10 Divisions in a RM (or whatever many).
Point is that an appuser (Android/iOS) only can be in one of them or am i wrong?
- So only the user in Division 1 are subscribing to a Topic for Division 1.
I just do not get the need for request hundrets of Topics (or how many you need to subscribe to)?
Based on the info i found online the amount of Topics subscriptions are not Limited.
But you are limited in not sending to much subscriptions in a short time.
BTW: The Server Api (or even the Server REST Api) can manage (un)subscribing up to 1000 Token to/from a Topic with one Subscriptioncall.