"MUM, THERE IS NO PAUSE BUTTON!" setting/tag for games

The ability to tag certain games as being difficult to alt-tab from to respond to messages would be useful, since some people get antsy if you use Do Not Disturb for extended periods, if at all. This would allow those people to calm their damn tiddies and give me a minute to finish my round of Rainbow Six Siege or my hunt in Monster Hunter to respond to them.

This is a minor problem that not everyone will experience much - likely hardly at all - but I still think it would be nice, since I'm sure everyone has had the frustration of being pestered while doing something they can't necessarily stop at a moment's notice (or don't want to stop to respond to every damn message).

I think the tag of "There is no pause button!" would be suitable, and applied to games at the user's discretion under the Game Activity setting,