It's been a while since I read his book, but I believe Al Herrin said the Cherokee chased a ring on black locust bows, or at least he said something like "all heartwood".
I often wonder if there were different techniques for working wood with stone tools we don't think about today. For instance out here in Utah and Nevada there was an entire industry around taking short staves from suitable juniper trees, where some sites were visited over and over to remove staves from the same location at the tree healed, maybe 50 years later sometimes. The branches were chiseled at each end of the stave, and the sides scored with stone chisels and choppers. Then left alone for weeks or months to dry, still attached to the tree. As they dried, they would often crack loose, and pull away from the tree, and when the NA'S returned they would pry them out "pop" with a wooden lever. That would never occur to me.
So, fire shaping? Green wood shaping? Lots of splitting, but little chopping? I dunno...
I once had the idea to cut an elm sapling, but leave the leaves and top intact for a few days to speed drying time. Worked wonders. In two days the leaves were crumbly, and log was way lighter than green wood. I split the stave out restrained it, DIDN'T SEAL IT, except at the tips, and it dried without any checking, unlike almost any other stave ever has. It still had a lot of drying to do to be ready to work, but to me that means it lost a lot of internal moisture up front.
Lastly, inspired by the juniper technique above, I cut halfway through a standing ash sapling at the top and bottom of the stave I wanted, and cut away a strip of bark at the sides. My idea was that dry wood is stiffer than green wood. So I came back several days later (late summer btw) trimmed a few branches, bent the top of the tree over AWAY from the stave, and the stave split itself off as the rest of the tree flexed.
Probably lots we don't do anymore because we have steel tools.
