Turning off all notifications except for direct-to-you seems reasonable, unless you're being paid to be on-call or something and it's truly critical that you be responsive to the team notifications? Batch checking it every few hours at a specific time. I've started doing this with slack/discord/etc. anyway, although I'm still responsive to signal -- and I wish there were a better protocol for "signal by default doesn't notify, but trusted contacts can choose to notify if they want".

(My first thought: Oh wow, I would be tempted to try to get an ADHD diagnosis if it got me legally immune from Slack (and Teams, ideally), and forced everyone to use Signal, IRC, or some other less disgusting systems when interacting with me.)