In Marder I read that in 1918 most of the big british shells were of a new enhanced type, that would have gone through the german armor, exploding inside their ships. If this is correct, it should be included into the simulation, making the german operation even more similar to a suicide mission.
To confirm William's recollection: In SAI, the RN loses its magazine vulnerability starting in 1917 and its shell penalty in 1918. These reflect the findings of the Protection Committee in the wake of Jutland and the Admiralty ordnance study that resulted in the improved projectile designs and quality control. However, due to manufacturing, economic and logistical issues it took some considerable time for the new munitions to reach the Fleet.