I'm not to into the weeds of activitypub yet but in my head it seems like you could add some things to the protocol to optimize this. 1. server with the sender

I'm not to into the weeds of activitypub yet but in my head it seems like you could add some things to the protocol to optimize this. 1. server with the sender constructs a map by receiving server that contains a list of all users on that server who should receive the message. 2. sending server iterates the map. If the receiving server has multiple recipients do a check to see if the receiving server supports this kind of 'bundled' delivery. 2a. If so send the message once with a list of receivers. 2b. receiving service processes the one message and delivers it to all the users. 3. If not sending server sends it in the traditional way, multiple pushes.