If you do a lot of thermaling they likely will show some benefit in a slightly faster roll rate. However in cruise if you are not flying absolutely in trim they will shed a vortex that just creates drag. It may be better to make the gap as small as practical and have the two sides of the gap smooth and parallel. The ASW-19 wing is very flexable; closing the gap fully or even almost fully will result in binding or even locked ailerons due to the flex of the wing.

Robert Mudd
Composite Aircraft Repair
Moriarty, New Mexico USA.