Great story, gd. I hadn't realized they could fly THAT high.
Mine usually get maybe a couple feet of the ground during the morning exercise runs. Most of my fences are 4-6 feet. I did have one end up on the other side of a 5 foot fence a couple times and not know how to get back. And yesterday I checked on them during their evening trip into the chicken yard (chickens and geese switch yards for the last hour of the day or so) and saw one of them on top of a 4 foot stack of pallets and very excited to be there!
When I used to run a huge flock of chickens along with small flocks of ducks and geese at my other home, I had them all trained to come when I called. I didn't mean to, but when I got the ducks I'd call them "Duck-duck-duck-duck!" so they learned to come when called. Later I got a bunch of chicks and would call "Chick-chick-chick" to give them treats, so they learned. Same when I got geese. I only took the goslings outside with me, since I didn't want to lose them to anything, a d I'd call "Goose-goose" as I took them to a new place, since they would seriously panic if they looked up and realized I'd walked more than 7 feet away.
All that lasted into their adulthood. I'd feed each group separately, calling the ducks first (they were piggiest), then the chickens, moving away with a few veggies for the geese, and finally hiding the food for the silkies (the last addition) on the other side of a row of bushes, since they were so passive they'd never eat if I didn't hide them while all the others were occupied.
My current flock knows what they are all called too, and respond fairly well. Except the guineas. They seem -- I think -- to know when I am calling them, but they won't come to "Guinea, guinea!". They sometimes come if I clap my hands. My current geese know they are "Goose goose!" but tend to come in their own sweet time, just to let me know I am NOT the boss of them anymore.