Separate shell types for min and secondary guns

[supermagnus2]

So take the Nelson Class as an example the main 16 guns fired light shells and I don’t think every gun on that ship class did, so setting the shell weight to light works on the main battery but not the secondary and I think the Ability to set them separately would be nice to have the same could be done for propelent 

[coalminer]

in a similar vein to this, setting primary and secondary ammo type in battle is crucial but missing currently. most times the main and secondaries would be engaging different targets (typically BB vs screening light vessels <CA) and running full AP/HE on is not as efficient with the correct ammo type being used on the targets.

Being able to choose the propellant type for both secondaries and main would allow for optimising the gun types (e.g. favouring penetration strength in mains vs fire chance/shell damage for secondaries), however im not clear if this was practiced historically or were shells just crammed with the same propellants to varying weights. This would also work the same way for shell types in that heavy shells for mains for penetration and sacrificing RoF vs higher RoFs for lighter guns.