I view this like J walking or not coming to a complete stop at a stop sign. 99.99999% of the time it's perfectly safe, but illegal if you get caught, so most everyone does it because getting caught is very remote, and most cops turn their head. Just think of what it would take to get caught. A neighbor that doesn't like you, hear the drone, then without informing you, call the cops. "Hello, police dept? Yeah, my neighbor next door is flying is drone in his back yard". Can you imagine the priority that would get during Covid19 isolation? Remote risk. The police would likely feel it's appropriate to stay home to fly. Then, if the cop came to your house, he would have to see you flying it in the back yard to cite you. Remote risk. Personally I wouldn't hesitate a second to test a drone in my back yard 6' high, but I rarely do, and I don't live near an airport. It's my back yard, private space. I can lay out naked in my back yard if I wanted, but I don't. Just don't fly above fence line so the neighbors can see the drone. They might think you're spying on them while hovering suspiciously, which may change the context of the neighbor calling the cops.