If after 9pm M-F, and I plug it into AC Power (Not USB on desktop), then it mutes all system sounds until I unplug it from the AC power. During said time, if certain people call, it raises the ringer to full so I can answer it.
I still have this enabled, but rarely ever use it, it came in handy about a year ago though - when near any of the WiFi hotspots at my work, then turn volume off, upon leaving the range, volume comes back up. Also, enabled my work profile which set an Autonotification to set a timer on my phone and watch for my break and meal periods. I now am full time WFH, so neither of these come in to play.
While connected to Car bluetooth, cancel my work timers (above).
I was working on but had to put on pause, a Google Voice interceptor - the goal behind it is to auto use Google Voice to make outbound calls if you are not calling a contact in your list otherwise, if you called one of your contacts, it would use your normal phone number.
Taskernet share for above (Google Voice Robot) If link is broken, it should be searchable. It's not guaranteed to work.