I love playing as Meth Cook, it's the role that I play as 90% of the time I'm on the server. My biggest issue with it though is the amount of ingredients you can buy at a time.
As of right now you can only buy 6 of each till it caps out which doesn't even fill all 3 pots or jars, I feel it would make sense to let you buy just enough to fill all 3 pots and jars at once.
So instead of 6 of each you'd be able to buy
20 Muriatic Acid
10 Water
15 Liquid Iodine
15 Liquid Sulpher
I feel this would make the Meth Cook job much less frustrating, The pot amount would still be limited 3 each making it so Meth Cook doesn't become an OP money printing machine but it would still make the role much more enjoyable.