I flew a G-26 in a Dynaflite Chipmunk that was fully sheeted and glassed. It weighed 20 pounds, and I didn't have any problems. It was no screamer, but would loop easily from level flight. Aerobatics in line with the design were easy as well. It depends on the plane. The G-26 is used a lot in 20 pound WWI Fokker D7s from BUSA. No complaints that I've heard as long as the weight doesn't go up too much. I'd think that the Zero would fly fine if it didn't weigh over 17 pounds.

Just my experience, and opinion. Good luck.