Sorry for hijacking your thread. I am describing another Laddermill. After more consideration, I lost faith in my idea quite quickly
I think most ground station issues may be solved by having only one kite. With only a single kite the idea is approaching normal Yoyo design.
An out there option is to completely detach the kites and let them fly back to the rope near ground, then somehow reattach to the tether. Could be possible if you can detect the tether from a distance with high accuracy.