"draw knife coarse". You haven't seen Curtiss Buchanan work one
. The DK is in fact a way underutilized tool IMHO. Unlike soled tools with a mouth, though, it requires understanding of the grain.
I concur with Chris C, below: take off the corners, then the hump in the middle up until the final passes.
Convex spokeshaves are difficult because they require the user to maintain the same angle through the pull. This is much easier in a tight curve, where the radius of the piece and the sole of the ss are close to matching. On shallower curves, the sole can rock and react through the cut. This can contribute to chatter. Good skill to master. I submit that for shallower curves, it's not only easier to use a flat bottomed shave, but in fact better, because it can 'fair' the curve more true than a convex bottom shave.