Any concrete info on when Apple apply server side APNS throttling?

We have an app which gets sent APNSs by the server and use a Notification Service Extension to intercept them.

In my observations I've never seen throttling applied on the device to these pushes (unlike app directed push where its easy to observe happening if you let the batter run low for example). The Apple documentation says it may perform server side throttling, but when, how often, under what circumstances? If the app has 30 million users and the server sends them 10m or 100 pushes per day will it get throttled?

Does anybody have any have any documented or observed info on this.

Any concrete info on when Apple apply server side APNS throttling?
 
 
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