FWIW, unconfirmed 3rd hand rumor from a couple (reputable) dealers I know is that ATF has a stick up their rear about the size or wt of the frame, which is imported, tho no one seems to know exactly why.
rcently purchased a Custom CDP at my local Kimber Master Dealer. Asked about This weapon in particular. He has never seen one outside of the Kimber catalog, and he has at least every size of each Kimber in the catalog, except the Polymers.
That damn gun is advertised in every issue of any gun magazine I get but they are not really for sale yet. Strange that the ATF would have such a hangup about a compact .45.