The tech guy at Woodcraft sent this to me. An unturned, assembled Cigarillo pen. The twist mechanism does operate, the refill extends and retracts. If you look, you'll see that the center band is even with the end of the brass tube. When the upper body is attached to the lower body, there is a very slight gap, maybe a thousandth or less, between the bottom of the center band and the twist adapter. So that tells me the problem is the center band binding against the twist adapter. But the length of the tenon would be absolutely critical. Something apparently I didn't achieve in either pen I turned.
I found something interesting in one of the reviews on Woodcraft's website. BH stated in 2018, "However the directions are not the best way to assemble the pen. If you put the pen transmission in the cap as the directions state the depth is extremely critical and it is very likely that the pen won't twist easily. It is far better to assemble the body first with the screwed on transmission then press the assembled cap over leaving a very small gap between the cap and body." I would like to try it, but I don't know if I want to turn another one to try. Maybe I'll see if I can disassemble one of the caps I've already turned. It will likely damage the twist mechanism inside, but Woodcraft sent me another.