Hi,
While I am not to familiar upon the twisting action, I was thinking possibly just one trit in the body and the 2 in the tail.
As got lumans pointed out a tactical or feel thing might be easier to do, cheaper anyway. there should be enough meat in the tail cap to mill/drill two different shapes into.
Overall, I think I prefer nothing because it is straight forward as you designed it. - K.I.S.S.
One more thing I though of while looking at the photo, what do you think about rounding the ends of the head and tailcap.
--I am thinking along the lines of slightly rounded so the edges of the hex meet the body flush. The same radius on the outer edges to match.
---This would make it more pocket friendly and snag free for a quick draw.

--- Even the edges of the nuts in your first post are beveled, granted the bottom of the bolts are not beveled.
xpshooter