I have been exploring a method to send messages in batch and came across the concept of Device Groups.
https://firebase.google.com/docs/cloud-messaging/android/device-group

Since there are CRUD operations available on a Device group, my assumption is that it is reusable. Is there any expiry on a device group?

Also, what is the limit to the number of device groups we can create.

I have tried doing a POC by creating Device Groups for my FCMv1 project and I couldn’t figure out if there is a limit to creating groups. For my dataset I was able to create 75k groups in one go.

Also though it is mentioned that the limit is 20, I am being able to add a payload with 100 registration ids for one device group.