I've done it on small pieces for thread painting, no accidents but not for the faint of heart. I LOVED it cause nothing obstructed my vision and there was no foot to catch my basting threads.
I know I've seen video's of industrial sewing without feet ... an environment where speed was a factor. Some were current and foreign (no OSHA to worry about) other video's or photo's that were taken here in the states were much older (pre OSHA or H&S in Britain). All of them were specialized where the same motion was repeated piece after piece.