If youve already got a multipler on the server you might have to ignore it by adding ,blgnoreMultiplier=true.. for example:
ConfigOverrideItemMaxQuantity=(ItemClassString="PrimalItemConsumable_WyvernMilk_C",Quantity=(MaxItemQuantity=50,blgnoreMultiplier=true))
ConfigOverrideItemMaxQuantity=(ItemClassString="PrimalItemConsumable_SweetVeggieCake_C",Quantity=(MaxItemQuantity=50,blgnoreMultiplier=true))
ConfigOverrideItemMaxQuantity=(ItemClassString="PrimalItemConsumable_Honey_C",Quantity=(MaxItemQuantity=50,blgnoreMultiplier=true))