As a generator of low speed lift, or as a generator of lift for low structural mass, it's extremely efficient. Ditto achieving a functional wing for very few parts.
If I understand you correctly - you basically want to reduce profile drag? That means the short of exercise Bill Brooks did when he created the PulsR, *or* incorporate the basic wing structure into a conventionally controlled aeroplane - a bit like the Verhees Delta?
If you can do that, and retain the foldability for transport and storage of a current Rogallo wing, you might do something quite worthwhile.
G