Of course powered - up to 1hr flight, altitude record is 5500m and distance record of 45km. I wouldnt do proximity flight with a model when you can do it once going up and down the hill.
I think they could try for speed record also - these kind of nonpowered wings do ridge soaring and dynamic soaring - specialized nonpowered gliders hold RC speed records now ca. 500mph.
These wings fly up to 250kmh with crusing speed of 50kmh.