Using curly grain on an impact tool isn't a good idea. It doesn't have the same kind of strength.
Also, Desert Ironwood (as gorgeous as it is) offers the same advantages as lignum vitae with the same drawbacks--I'm concerned about the impact being transmitted to my hand.-- And it's not as tough.
Cocobola is a type of rosewood. Lots of trees have sap that cause contact dermatitis.
Osage orange is good for bows because of its long and stringy fibers. Unfortunately, I've seen what can happen with osage orange handles on impact tools. They can split right down the center into thousands of footlong toothpicks. The stuff is hard, dense, and resistant to decay, but it's still not as good as shellbark or pignut hickory.
I'm looking for something > hickory, not just a replacement.
Also, I don't really mind the weight. I know LV is denser than water, but consider how dense hickory is. LV is only ~1.5 times heavier, but is several times tougher. I don't mind the difference between a 7 and a 8.5 lb axe+handle- plus it brings the center of mass down closer to the hand - easier to aim.
There are lots of French words that make it to the US and get Anglicized. Prime example: Detroit. Should be pronounced deh-TWAH, but it isn't. (another example would be "Rue de la Roi" which became "ruddy road") This happens because a relative few speaks French in the US. There's honestly no reason for this to become an argument, let's just move on.
Does anyone have experience with a wooden handle that transmits too much impact force to the user? I'm dying to know.