Valve has released patch notes for the Steam Deck’s latest update, which include the very welcome addition of game-specific performance settings.
To access this new feature, users must simply hop into their deck’s ‘quick access menu’, and then select the ‘performance’ option. From here, click into ‘advanced view’.
When the per game settings are then toggled to the ‘on’ option, a “profile for the currently running title is created.” Once you have edited the settings in this profile to your liking, they will be saved and applied automatically when you launch said game.