The game is highly CPU bound. To reduce stuttering it is hightly recommended to set GPU clock manually to somewhere between 800 MHz and 1200 MHz (down from the max 1600 MHz). If the GPU clock is left on auto the Deck often does not allocate enough power to the CPU leading to very low FPS depending on the scenarios (way lower than 30 FPS). Lower value gives move stable FPS while higher value gives better graphics fidelity. Enable dynamic resolution scaling and target 30 FPS with minimum 66 resolution scale. Make sure to use Deck's frame rate limiter to 30 FPS and not the in-game frame rate limiter as the former gives more stable frametimes.