I had a pullet start laying in the middle of this past December, just before the winter solstice, the shortest days of the year. I do not provide extra light either. I have pullets that are not laying as the days get noticably longer. Some will lay, some will wait. Can't argue with Fred on that.
I had a broody wean her chicks last summer at about 2-1/2 weeks. In the heat of summer, i don't wait until 4 weeks to turn off the heat. In fall or winter, I keep heat on longer.
I brooded chicks last fall. I brood in the coop, not the house. By the time they were 5-1/2 weeks old, they were in my grow-out pen with no supplemental heat. The overnight low was in the lower to mid 20's. If it were the middle of summer, they would have been out a week or more earlier.
I'd change OKChickens requirements to they need heat, food, water, and protection from drafts. My brooder floor is wire, no bedding, but I have a good draft guard. In some brooders, bedding would help. Just different ways to do things. I also believe it is hugely beneficial to only heat one area of the brooder and let the rest cool down a bunch. They'll find where they want to be.
About the only disadvantage to me to a fall hatch is that I raise mine mostly for meat and forage is not as good in the winter months. Eggs and when they start laying is not that important to me. I wound up paying more for feed to get them to butcher size with a later fall hatch due to poorer forage. I'll try to avoid that in the future. Other than that consideration, if I hatch my own, I hatch them whenever I want to. I have a generator to power the incubator or help provide warmth if we have a power outage.
If I am getting them shipped, I try to avoid getting them in severely hot or cold times of the year, preferring to ship in milder weather. I've yet to have a dead chick in a shipment, but in fairness, I have not really had that many shipped. I avoid postal holidays too.