I'm not a big fan of IWB small-of-back, but it's about the only option for my wife. She's none too big at 5' 3" and 125lbs, and like I mentioned, it's awful hard for her to conceal much more than a credit card under jeans (or dress slacks) and a fitted T or blouse.

My personal favorite carry position is front of hip IWB with a minimalist IWB clip holster (still trying to find a Techna Clip for the wife's LCP, would love one for my LC9). The problem I have with SOB IWB or FOH IWB is the bulk of the holster. Most IWB holsters aren't designed to form fit the body, nor the clothing, so they're uncomfortable, or printing/shifting becomes an issue. The Supertuck is remarkably comfortable, but it's also massive, and still has the outward printing issues.

My thoughts are to make a minimalist pancake style two clip that's structured at the top strap and trigger guard/underbelly to taper, rather than have abrupt corners.