Hey James, I checked out Heritage LB. Bows look good.
I did a bunch of experiments with caramelized bamboo flooring about 20 years ago. They were all laid up flat with no reflex, (the days before I really appreciated Perry reflexing). I found the material performed well. It was really pleasant to shoot, like yew, but took a lot of set.
It obviously performs very well for Heritage, when reflexed. I think you could get better performance making your own, because the mass produced nature of the commercial boards aren't made up the very outer fibres where the strongest material is. Carefully hand selected and prepared you could ensure maximum power fibres.
It would be a hell of a lot of work, but I have heard of some guys doing it.