Good video & discussion!

I would personally question the energy expended by the drone difference in hover vs normal flight & maneuvers. It probably depends on your hover height & the type of maneuvering you do & how turbulent the air is for your drone.

If it's a 20+ mph wind, you can often hear your drone self-adjusting power to keep itself level. Power adjustments consume more power than "no change" power settings. Of course, with the computerized synchro controls necessary for quad copters, we don't know or control these power changes, but you can hear them when the drone's near by.

I suspect with the Inspire hover vs battery time video below, the Inspires may actually have been in some ground effect. As many fixed & rotary wing full-size pilots know, it takes less power to fly (= hover) in ground effect than when out of g.e. An example of this happens when an aircraft pilot "horses" a heavy full size plane off a grass strip thinking he's going to clear trees at the end of the runway, only to find the plane does fly OK @ 5' of altitude, but he can't climb to clear the trees. Sad scenario. He was in ground effect & couldn't get out.

I also wonder if the parasitic drag of the drone moving forward isn't greater than that additional lift that is generated by the "advancing blades" meeting airspeed due to forward motion. There is no free lunch & drones w/cameras hanging under them aren't very aerodynamic, though at the relative slower speeds it's not a big deal. But, regardless, the drag is there to some degree.

Finally, can anyone confirm to me that DJI has pre-programmed to descend slower than normal to prevent these rotor stalls? I've always thought the Phantom 2 descends very slowly, regardless of stick position.