And you might find that scarfing the last four inches of a board on might be counter productive. It might well be better to scarf two five foot two inch pieces or some other similar combo of lengths. Adding a scarf and concomitant glue line right at the end can sometimes lead to less happy bending right there. If the piece is gonna be largely flat'ish it wouldn't likely matter. It partly depends on your capability to scarf a long scarf in small wood.