Not in complete disagreement, but October is a normal time for hens to decrease/cease laying, depending on your climate and location. Sometimes even sooner, esp when molting is factored in. Climatically speaking, this year has been, overall, wetter than average and much colder in the majority of the country. I'm open-minded to other possibilities (there is always some feed or other being recalled, etc), but the historic data tends to favor factors other than feed additives being the cause.People who feel the need to say things like "Period" and make snide allusions to others being ignorant or any other belittle remarks usually aren't people who are very informed, honest, or feel secure in their position.
I was well aware that chickens slow down in the winter months. I researched everything I could when I got my chickens and knew what to expect. That's why I thought everything was normal at first. I was expecting a slow down, but I was very surprised that it was a literal completely stop to laying. You claim chickens usually. Well on this feed I'm using, they haven't and they've been laying like normal. I've read the same from plenty of others who have had years of experience. They said they've never not had any eggs. Fewer in the winter months than normal, yes, but still producing. And for some people, this began for them in October.
You should look into what people, new and experienced are saying, then reread your last paragraph. It applies to you more than anybody else.