The threading is the same they are all M12 Board Lenses but I've only changed out stock GoPro 3 and 4 lenses to lenses which are not as wide a field of view. Never tried GP2 The Yuneec lens has a 4.65mm back focus. The GP3 and GP4 stock lens will easily screw in and it should have a back focus which is compatible to the Yuneec camera. I would never do what you're contemplating however because that lens is much too wide for good video and stills in my opinion your props will show in every photo and every frame of video..the stock GoPro lenses have a field of view of 160 degrees, the stock Yuneec lens has a field of view of 98 degrees.
Yes, you are right!!!