Mom Had Better Fur!
Our first few feedings with litter 15 went better than we expected, with all four kittens getting suction on the nipple most of the time. The rubber nipple probably feels strange, and I doubt the milk is as good as Mom's, but at least it's warm and filling.
One little guy (bk4) even started purring audibly after he was done drinking. It amazed us that a kitten this tiny would purr. Maybe it's part of the "bonding-with-Mom" process?