Goose advice appreciated

I'm looking for any tips to better my two American Buff's lives. This is my third variety of bird after chickens and quail, and I don't have any specific concerns. North Carolina, USA.

28 weeks old. They free-range on 1/5 fenced acre, with access to another 1/4 acre under supervision.

50 gallon stock tank with heater (to prevent ice, keeps it about 40°) for bathing, multiple sources of fresh water throughout their yard.

They're getting the chickens' layer feed, with a bucket of dried Timothy and alfalfa grasses. I split an apple between them every other day or so.

They sleep in a metal shed with pine shavings underfoot.

I'm fairly sure I have a goose and a gander by size and behavior. He is getting more territorial, but not anything i worry about yet. They hate certain people in my house, will still sit with me and take a nap. Had them tested at my last NPIP/AI exam, and they're free of the diseases of concern.

Is there anything you have picked up with your geese that I should maybe be thinking about? Or have I already set them up to be spoiled little boogers?