Sometimes sudden changes in weather or moulting will cause chickens to go off feed for a bit. I'm unfamiliar with Scratch & Peck, if that is a brand. I've witnessed chickens rejecting feed over the years if it is a powdery crumble. I prefer pellets. Bar Ale is making a soy-free-GMO free ration that is better than others I've seen since sunflower meal and fish meal are the replacements for soy. Add some Avian Super Pack and some Probios dispersible powder to the water if they are off feed. That will help them out during reduced feed consumption.
I'm interested in Scratch & Peck because people have found that the chickens like it. One of the three organic brands you mentioned was extremely unattractive to the flock. I attempted to do the standard change over of cutting a small amount in an gradually increasing it, and they rooted around, ate the Purina crumbles. ,and left the organic feed in the feeder or billed it out, maybe eating the parts they liked..
Scratch & Peck uses fish meal; a lot of feeds at one time used fish or crab meal - now it is almost impossible to find any that do.
I might try the Bar Ale if it uses fish meal.
I'm not particularly concerned about GMOS, call me a heretic, but plants have had mutations for centuries. I do avoid alfalfa sprouts because the non-coding amino acids can cause inflammation in some people.