My guess is there is a custom setting that defines the status of the gaming mode. That's only a guess since I don't have a One plus.
You could use the native tasker settings -> custom setting action to see if you can identify what changes when the game mode turns on. Tapping the magnifying icon will bring up an assistant. Once you identify the setting, it can be used in a profile context (system -> custom setting).
From some online reading, I also think that the games that trigger game mode are entered in a list by a user. You could use an app context with each of those games selected so your profile activates whenever the game is in the foreground.
Hitting the gear/cog icon when the profile is selected will bring up settings for the profile. One of those settings is a toggle for restoring settings when the profile exits. In the case of an app trigger, when a different app is in the foreground, the settings made in your entry task will revert.
|Thread Tools||Search this Thread|