There was a NASA (or NACA depending on when it happened) project to study that for small planes. They found that you can droop the leading edge for the outer third of each half span to do what you're suggesting very effectively... only trouble is, it's quite visible the way they found it to work best (no transition, just an instant change at the designated spot), so it would look unscale-like on most planes.

The other consideration is that you won't be seeing a whole lot of snap rolls from a plane that won't tip stall, if this is for an aerobatic plane, be careful what you wish for!