Well, I see I'm still being talked about!
No, Smartcarry isn't designed to have a holster inserted into it. I finally found one at a gun show to examine and except for the cotton padding (or whatever material they use) it isn't really different from what I had. The cotton padding isn't thick enough to prevent an AD with some weapons. As for putting Kydex in it? I doubt it as it would be pretty tough to sit down seeing as Kydex doesn't bend.
If you need to carry well concealed there are better options. The Kangaroo holster, or the Deep Conceal holsters are worn under the shirt, they are comfortable and a whole lot safer. If you are going to carry deeply concealed you need to match the gun to the holster. Find a gun that's double action only with a very tough trigger pull, or with a slide (and not a frame) mounted safety. An example would be the S&W Bodyguard .380 and NOT something like the Sig P238.
And Salmoneye, I'd say you're making a good choice in having nothing to do with it. Remember folks, neither holsters nor guns come with an Underwriters Laboratory testing seal. There's a number of unsafe holsters out there that are being sold on hype, so buyer beware.