@Wetrix I was thinking of something (sometimes my brain does that)

In iOS to have push notifications the developer has to generate a push certificate in the Apple portal and install this certificate on his server to get push notification to apple. Apple will then deliver them on the phones with that app.

I am not sure but I guess the trouble is that for instance Amaroq pushcertificates aren't of course installed on all instances in the Fediverse.

Or do I miss the point here?