Notification flood when catching up with MAM after being offline

Every time I keep my phone offline for some reason and have a XMPP conversation on some different device meanwhile, I get tons of notifications after putting my phone online. When the conversation was very active it gets pretty annoying waiting for the phone to stop vibrating and making noises.

In such cases, sending a notification just for the latest message in the conversation would be definitely enough. Bonus points for not sending such notification if it can be deduced that the message has been already read on a different device.