You know, I was actually worried that my insistence there would make people think it was a bit lol But no it's genuine, there are only three bottles to be found.
And there is actually an immobile ending, but you need to find all the milk bottles for it. You can either return to the Base with all three, or you can drink one and mix it with the other two regular milks. I don't remember my reasoning for the weird formula, but there's a chance I'll revisit the number of milks and revamp the general formula for it.