this would send all the subcompact semi crowd screaming 'no fair', i would love to see this (as i have somewhat created it by modifying a 327 to shoot 9mm); just as many shots as the shield, easier to carry in my opinion, revolver cylinders follow the contours of the appendix iwb carry lines almost perfectly.
moonclips for fast reloads or but machine the cylinder headspacing so that, in a pinch, you retain the ability to speed-strip single rounds in like the LCR or 986 etc
rear notch sight machined in like 327 with tritium, bigdot-ish front sight for smooth drawing, quick targeting...
think 8-shot ruger LCR-ish