Boy do I feel dumb! I actually tried it (had to be in Smart mode). First time I hit the button it told be aircraft was not ready. Finally, I tried it again, gave me a slider to activate and it did take off and hover at about 4' or so. I just assumed (I know, I know) that red meant not available and green would mean ready, or something like that. Yuneec uses other icon colors like those mentioned and yellow for various status. I guess it was just not intuitive to me nor well documented. But it works. However, I did notice that its more "tippy" with taking off in this mode vs. using the throttle stick. I'll stick to the ole fashion way and take off a bit faster - more stable that way.