Nice replica!
If I remember right, the deal with the extra wings was to not so much produce more lift overall, but to greatly reduce the required turn radius. The great strength of the Dr. I was its ability to slew around at low airspeeds, and in general nothing in the air at the time could turn inside it, even the Camel. It also seemed to do very well in extreme mushing flight- sneaking under enemy planes and raking their bellies with fire was a common triplane tactic.
I think the short takeoff runs have more to do with the power-to-weight ratio and the airfoils themselves: the original Dr. I sported 110 hp for a 1200-lb. GTW plane with a high-camber airfoil.
And I'll bet this replica has an even more favorable power-to-weight ratio, and more efficient airfoils...