I read somewhere that the Engine torque of the DR-1 was enough, at full revolutions, to keep the pilot from flying it in trim. The solution to this was asymmetrical Ailerons (The left one was actually one rib length longer than the right) to correct this problem.
Another thing about the DR-1 is that the length of the fuselage was considerably shorter than that of it's contemporaries. This, coupled with the foreshortened wingspan, allowed the plane ( because of the balance (moment) of the shorter fuselage, along with the Triplane design which allowed for more wing area and greater lift) made the DR-1 an extremely maneuverable plane. The only plane that was better than the DR-1 (from the ease of flying perspective) was the D-7. That plane head it all, Speed, Strength, balance and stability.
At least that is what I have learned over 45 years of playing with airplanes.
Tee