I can remember racer friends back in the day experimenting with doubles on their road pedals, but they eventually went back to single straps. Of course, they were wearing bike shoes with cleats. Doubles are really a track thing, but of course that's where fg riders get their inspiration.

Personally, I agree that a double strap with sneakers isn't necessary. A single strap will keep your foot to the pedal, and is easier to loosen, should you tire of track standing.