My new job we use Teams (which sucks), but has configurable quiet-hours. I have mine set to only notify my phone between 7a-7p, and only when I'm not active on the desktop. Helps quite a bit, except I do sometimes miss notifications. So it goes. If it's _that_ important, they'll call.
7a-7p is a very long window to get slack notifications. I'd tell an eng to cut it to 9a-430pm or something if I heard they did that (assuming a usual 8-5 / 9-5ish).
I never acknowledge any slack message before 9am my time. I did that at one company and realized how absolutely miserable it would make me when I was getting dressed in the morning to see some fire going on or request or anything work related before I was "on," even if I wasn't really involved.
