I went for these setting as I couldn't really see a noticeable different with the settings set any higher.

Graphics are set to
OVERALL QUALITY FASTEST
WATER QUALITY GOOD
TEXTURE QUALITY GOOD
SHADOW TYPE SOFT
SHADOW QUALITY GOOD
SHADOW CASCADE FOUR
REAL TIME REFLECTIONS GOOD
VYSNC ON
ANTI-ALIASING ON
AMBIENT OCCLUSION ON

*Note steam deck is running CryoU Utilities recommended settings.*

Gpu clock is automatic. Averages about 800-950mhz playing

Overall really good Graphics and power consumption