We published an android app with firebase FCM notifications and we had 100k+ registrations on FCM database. When we tested the notification on the users it takes hours to process and sometimes it's hanging for a while (due to 1000 limitations)
We noticed the TOPICS features on FCM that is more appropriate for broadcasting notifications.
Question : Is there a way to copy all the users to the newly created/implemented topic directly on FCM DB without updating and waiting that all the users download the new app ?
Thanks Willy.