RE: Minimum Hinge Gap
Well I looked at the pictures and the manual also, couldn't find a reference to what type of hinging they used.
Just a chance since you can't see a hinge gap, they may have done as they did on the Hangar 9 Camel. Instead of actual hinges they used the covering itself for the hinges.
Would have worked out fine if the ailerons were chamferd on both sides, but in fact were only chamferd on the top. On my Camel I ended up cutting the ailerons off the top wing and rehinging them as the covering on the bottom was so tight it wouldn't allow the ailerons to move up.
Worked out great for a few years, then had to redo the bottom ones also as the covering was letting go and the ailerons were just moving back and forth instead of up and down.
Guess that why they call them "Almost" ready to fly.