Include salt in dry premix?
I say, go ahead and include the salt with the dry ingredients. Polar or non-polar may be critical if you are in a chem lab, but in the kitchen this is my reasoning:

1) Most recipes I have seen for baked goods, call for mixing the salt with the dry ingredients.

2) I have never seen a commercial mix (biscuits, pancakes, cakes, muffins, etc.) that ever called for the baker to add salt to the mix, making me think that salt is included in the mix as purchased.

Maybe the polar/non-polar thing is less important than convenience.