BGB, I have used them all, and from my experience, some bias limbs will want to go sideways, and some will be fine. Usually I make the bow a little long in this case and keep the limb cross section thinner and wider than an elb deep core style. I have used edge grain on a few bows and had good luck, although I don't think its as good as a perfect flat board, its not much of a detriment either.
Avoid swirls since ipe being so dense. any fluctuation in this is a problem. since these are small and you cant leave wood around them as we do with other woods on the back of a bow..and on the belly its where it will collapse..
Hope this helps,
Rich