If a flexible kite can behave like a flag during the reel-in phase, it will be good for a more or less significant reduction in the drag (which remains nevertheless quite important), although bad due to more wear. Using a rustic kite a parachute in aligned (no crosswind) flight would likely not generate positive energy because, even in “flag mode” during reel-in phase, the apparent wind speed (real wind speed + reel-in speed) cubed would lead to a more or less equivalent power consumption than the generation power resulting in a far lesser apparent wind (real wind speed - reel-out speed) cubed.
Drag Force, Velocity, and Area Calculation :
Flag (C values from Munson et al., 1998)
A=DL
C=0.07 if L/D=1
C=0.12 if L/D=2
C=0.15 if L/D=3
The drag coefficient decreases as L/D decreases, possibly due to a lower flapping amplitude.
I agree. But in the end the control to keep a minimal traction remains required, and the configuration becomes close to that of @Kitepower 's leading edge inflatable kite (not like a flag).
Today I experimented the same 2 line kite with a 3rd line connected to the trailing edge (photo and video below): the kite remains probably uncontrollable while drag is a little mitigated (as for a flag), but not so much.
So I understand better why diminishing time and traction during reel-in phase is so difficult, if it is really possible.