I'll admitt to having taken off twice with the canopy not latched. It didn't have much consequence in our tip-up RV-6. I kept the speed down under 100 mph and got it back on the ground. I'm not the only one who has done it. A friend who owns a Giles 202, did the same thing with about $5000 in consequences. While they were making repairs, I suggested a small proximity switch, to detect when the canopy is not latched. It operates a small flashing LED on the panel. They installed it to operate when the avionics master is on. The current draw is 1/10 amp. I plan on doing the same on our RV-6. Just thought to pass it along.
Bob S
Bob S