Oh gosh, now that you point it out, I see what you mean! I checked the King Arthur site and their “Standard Bread Loaf Pan” is 8 1/2 x 4 1/2. I will use the true 9 x 5 pans for CL donations. Thanks for cluing me in to that.
I mixed this batch for 40 minutes total on my ancient KitchenAid, with a couple cooling pauses. The window looked good to me. Final proof was 60 minutes and seemed to pass the poke test, down from 70 minutes last time, which I think was overproofed. I will try mixing a little longer next time.
Thanks for your help!