This kind of confuses me...
With a traditional cheddar, I think you want to add the dry salt after you cheddar and mill the curd. During the cheddaring, the cultures are still working on acidifying, and you don't want to interrupt that with salt. Besides, with the curd still in big slabs, the salt wouldn't be thoroughly mixed in.
However, you're working with a stirred curd cheddar, which I have not done. I would assume the salting would occur at the same time (right before pressing), but in the recipe I have, it does say to add before the stirring/cheddaring. This is according to the Carroll book, which I don't fully trust though...
When you say 3 days, do you mean using brine to add salt to the cheese? Cheddars have salt added dry to the curds before pressing.
(edit) Sorry, I forgot you were using goat milk. It does say to rub with dry salt for a few days after it comes out of the press
I would still add it dry right before pressing.