my iphone is permanently in one of the focus modes and it works surprisingly well. it's work/sleep unless I expect a message or a call late night (sleep mode automatically declines calls.) there are some high priority notifications that go through in work mode, but honestly never bothered with figuring out how to make an app high or low priority or how to configure my own focus mode. it's enough for me that messages from my family pop up a high priority notification and most everything else doesn't.