Bill, Nick -- do you guys have something in mind to help the compatibility of small neck fisheye adapter lenses like the FC-e8 and the $49.95 IPIX one that I have and others have?

It's the dark half moon problem where the tilt axis of the upper arm protrudes into the field of view of a full circle image.

Like this --

Maybe something like a Bophoto thing that attaches to the upper arm horizontally and sticks out a few extra inches.