Hello everyone :)
Great news, my game Road Z : The Last Drive works on the Steam Deck, here is the right settings to make it works with a stable 40 fps.
In the settings of the game, set the screen resolution of 1280 x 800 and set the graphics to Medium and set the Shadow Quality to Low.
In the Performance menu of the Steam Deck, select the Framerate Limit to 40 fps and also the Refresh Rate to 40 fps, Turn ON the TDP and set the Watts to 15.
Have Fun!