Update! We can occasionally get Goose to step up on our fingers to get a treat now!! I'm so proud. He's still very reluctant and tries every other avenue to reach the treat first, though, and also the process seems to include yelling at the fingers before stepping up. We've been really struggling to find a treat that he liked enough to do something he didn't feel like doing... He likes a lot of things, apples, millet, seed balls, etc. but apparently not THAT much. I've been able to get him to step up to get the first seeds in the morning, and he's also extremely motivated to get a nibble of Juanita's corn chips...
We found that out accidentally, but occasionally let him eat the tiniest bit for a step up. I wish there was anything else he loved that much!