That's totally normal, it probably just means that he really likes what he's eating...It's the same thing they would do if we gave them a whole bowl of junk-food or something else they like, they'll eat themselves full. I don't think that birds are like dogs or pigs (or humans) where they will eat something they really like until they are physically ill, but they'll eat until they are completely satiated.
Their crops stretch WAY BEYOND what they normally do when they eat...I've had people who have never owned a bird before adopt one at the Rescue, and they'll call all freaked-out after the first couple of days because they don't think their bird is eating enough food because their crops aren't "visible", like they search online about what a "Crop" is, and read it's a "balloon" that fills with food as they eat, and they think that after they eat enough food their Crop's should be blown-up like a balloon. So when they can't see them they're worried that the bird isn't eating enough...So the opposite also applies, we typically don't ever see their crops balloon-up very often, so when they eat enough that they do blow-up like a balloon we get worried. But it's completely normal, and as big as Lincoln's crop was after eating that new Chop recipe, it can stretch probably 10 times larger than that or more before he'd ever have an issue...
Anyone who has ever hand-fed a baby bird without their mature-feathers formula knows how large their crops can get; I've seen some parent-birds actually over-fill their newly-hatched baby's crops, to the point where I was actually concerned they were going to die...But they're always fine, those things can stretch!!!
Too bad we don't have crops...We could eat and eat and eat, and we'd never get sick...Of course we'd all end-up weighing 500 pounds...
