Geese don’t exactly feed each other so there aren’t social issues with feeding geese by hand.
A dominant goose may chase off a submissive goose from food and a parent will let a gosling eat before they do, those are the only behaviors associated with food that I can think of right now.
Among the geese I’ve raised and spent the most time with they have no issues eating out of my hand. Leo is the only one that tries to bite me while I’m feeding him or the others because I wasn’t as hands on with raising him and sometimes he gets overexcited and it turns into frustration than aggression.
Hand feeding him though has gotten him to tolerate my existence more “sometimes” but with the others it seems to strengthen their appreciation of me.
I have one girl who will bite me if she feels like she isn’t getting as many treats as the rest, she feels under appreciated and lashes out I guess
Giving treats by hand is another way of interacting with them, and the more you interact with your geese in general the more they see you as family. If their only interaction with you has been when you feed them but then you leave they don’t really see you as a member of the flock, then they can get aloof and avoid you “more likely the girls will do this,” or they may even try to attack you for invading their territory “the boys are more likely to do this especially in breeding season.”
If they’re already like that hand feeding “if your brave enough” can help them associate you in a positive way, but not always. It’s really about how much time you spend or a previous owner spent with the geese that affects how friendly they are, giving treats doesn’t make much of a difference either way.