I've made tons of one yarder quick turn baby blankets with flannel and soft & bright batting and some of those are ten years old and a tad faded but otherwise fine
I generally quilt about 3-4 inches apart on those but that's mostly due to the small size of the blanket. I tell the parents to let the baby poop, pee, drag around and use the blankets, then wash and dry. I've never understood the flame retardant argument since smoke inhalation, CO, and lethal fumes from burning building materials tend to kill you long before the flames get to you. The soft and bright batting also dries very quickly in the dryer which I really like.