Dan I'd like to see the belly where that burl is. Consider that if its swirly there in that area that the wood may not have any integrity, like a knot, and should be treated like a knot, IMO, by not allowing as much bend through that area. If you were to steam and bend that area you would see it just crack open since the grain does not flow through. By allowing it to bend there you may be weakening it. But if the bow is kept long and the bend there slight then you may be ok.