Adding the ability to add spices already available in-game like black pepper, chives, kvann, etc. to curding tubs would give a new layer to cheesemaking. This could mean either new cheeses (harder to implement, maybe only a few spices to specific cow, sheep and goat curds make new cheeses) or just adding the FEP bonus to the cheese which scales down at each stage as to not make cheese already better than it currently is.
Another change could be adding lemon juice to the game giving fruit more uses. Lemon juice or vinegar is used when curding cheese, substituting vinegar for lemon juice to create rennet could be a new rennet interaction with each type of curd resulting in again either new cheeses or just different FEP buffs.