Tim, would you not have trouble with the bandmill wandering if you are cutting 3/8" boards? a slight movement could ruin shingle stock.

I would actually want to quarter the wood, as quarter sawn stock is more stable -this is the biggest advantage of hand split shakes over cut shingles.

If we can get good enough pine, we might go ahead and split it out by hand. Depends on the cost of buying enough sawn pine to cover bout 650 square feet of roof.