A little birdie told me John Ralson of 5-Shot Leather is prototyping an appendix rig. If true, then I can assure you it will be worth the wait; I am fortunate to have several examples of his work, and Mr. Ralston's leathercraft is second to none.
If he sees this, perhaps he can confirm the 'rumor' (?). If so, here's hoping his rendition of the APX trades the belt clip for a proper sewn loop. (I'd be surprised if it didn't, but maybe he can confirm that as well.)
Heck, maybe if we're real lucky, he'll even show us a picture or two.
(Hint)
-AC