What I wish I had is a way to silence multiple notifications when someone is texting you a bunch of times in a very short time (aka "blowing up my phone). One notification is enough -- maybe two max, and I'll check it when I get a chance.
Might be able to setup a system like this with Tasker i.e. if you get more than 2 texts from a person in a certain timeframe, then silence all the future notifs from them for a time
I use an app called buzzkill for this. It has a bunch of ways to customize notifications based on triggers, including the main one I use which sets a customizable cooldown for the triggering notification. So my group chat is limited to one notification per minute regardless of how busy it gets.