I think I figured out what the problem is/was.
Almost all the poop overnight is solid, and in the chicken run it seems pretty right for the 1-2 out of 10 ratio. However, I've noticed that when the chickens come out to graze and get treats, one or two of them will almost immediately release some of the sticky pudding poo. While they are out and free-ranging and grazing, the ratio seems flipped to where to pudding poo is much more common. This seems to be the case with all the chickens, and it seems to happen before they eat anything outside the run, so I don't think it's anything to do with eating too much grass or a problem with the treats.
I think this is what I've been seeing all along, as I'm much more likely to notice their poop while they're grazing, and I'm supervising them, vs when they're in the run they're on their own. I'm thinking/guessing it's excitement. Is that a thing? I've seen it happen in cats and dogs, but chickens are still pretty new to me. They love to be let out of their run and will fly from the back of the run to the gate whenever we step out the door. Any thoughts or experience with this?