Clever but, why?

All you're doing is making a lower poly version of V4 (which already exists in the geometries folder) and breaking compatibility with all LF2's content, except maybe her textures. So essentially trading LF2 for V4. 

If you're going to all that trouble of morph brushing then do it on the clothing to get a better fit around LF2 after the fitting room - because fitting room results aren't always that great depending on the item.