I am interested to hear more about what you found in your Janka research.
Purpleheart random thoughts. It is dense. Its end grain cell structure is different than others. Notice the little 'pits' in the end? PH is consistently dense, and does not waver much from one tree to another.....one board to another. Its so consistent, I don't think it matters about the tree size it is coming out of, or the growth rings out of one tree/board to another. Though, I don't know about the trees. I have never seen a PH tree.
All that said about PH, I think you are on a great path with the Janka chart.
ALL that said, I think you will find your domestic answer is hickory. And I personally don't think hickory holds a candle to PH. But, it is a great choice for a domestic wood, and I have killed several birds with it.
If you don't want to discuss this part any more, that is fine, just throwing my perspective out there: So, the side note of you not wanting to use exotics.....even with dymondwood at the root being a domestic wood.....PH is a whole lot more 'wood' than dymondwood is. Dymondwood is REALLY just a whole lot of plastic. I don't hold myself to the standards you are talking, I use them all, because I use the materials that make the best sound I can get for a field call. If a company were to say 'domestic woods' and then offer dymondwood as an option, it would make my mind skip a page or two.
Vince