I had the same thought about skeletonizing the handle, and that would also provide an attachment point for a wrist lanyard. I would go one step farther: flare the ends of the wooden grip and then wrap it with paracord. That would provide a better grip surface, the paracord grip can be easily replaced or removed, and you would also have a quick supply of line to use as a tether when you are using the axe up in a tree stand or on a ladder ,clearing shooting lanes,etc.
I thought about adding a nail-pry at the top of the blade in line with the handle, but that would stick out of a sheath and adds significantly to cost due to lost material in cutting out that shape. A pry/chisel could be easily added to the base of the handle but that would be an issue when using the axe unless it was covered, and that get's you into more complicated design and manufacturing processes, like a removable protective butt cap on the handle: a fancy threaded/knurled cap or a simple cap that slides on over the prybar and is secured by a brass machine screw threaded into the prybar section, maybe a knurled head / coin-slot screw like was used by Bear with the original screw-on bow quiver....Hey, maybe I should make an axe!