https://github.com/Lyall/MetaphorFix

Works out of the box at a locked 30fps at 1280x800 with max settings and 100% render res. You should probably install MetaphorFix by Lyall if you want fixes for analog control and full 16:10 display support, otherwise it default locks to 1280x720/16:9

If you want a solid 40fps you need to install MetaphorFix and tweak the shadow settings and LOD draw slightly alongside adjusting in-game settings.

In your MetaphorFix.ini file, change the following variables: [LOD] Distance = 7

[Shadow Quality] Resolution = 1024

In-game change: Ambient Occlusion to Off Texture Quality to Normal

After making those adjustments you can lock the game at 40fps/80hz using the Steam Deck's built in performance settings and enjoy performance that seemed only impossible a few days ago.