I'm saying these pilots want to do this innovation, not that ultralights are a large proportion of the problem, or even that GA as a whole is a significant cont

I'm saying these pilots want to do this innovation, not that ultralights are a large proportion of the problem, or even that GA as a whole is a significant contributor to pollution. But the reliability issue is significant: two-stroke engine failure is a frequent cause of ultralight accidents. They require careful maintenance and in-flight handling to be reliable.