Of course, we don't know what would have been considered "out of the ordinary" at the time. Modern Passover seders (especially as practiced in America) might not be an infallible guide.
Oh, I think the history of the ancient Passover is as well known as any other ancient practice, if not more so.
Unless one can provide adequate evidence that any ancient Jewish celebratory meal involved a host manually feeding guests, I think we’re on solid ground rejecting such a notion.