I believe all these will be true on Hard, and most not selected on Easy. Then you can also do a custom where you select what you want.
LimitedBatteries=true
LimitedCompressedAir=true
LimitedO2=true
LimitedFuel=true
RealisticRepairTime=true
ManualTargetingSystem=true
NoMapUpdate=true
RealisticSensors=true
DudTorpedoes=true
RealisticReload=true
NoEventCamera=true
NoExternalView=false
NoStabilizeView=false
NoShipHealthBar=true
NoGunProjectilePath=true
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