I had an old D-14 with all kinds of snap couple equipment.
sub soiler, pond scoop, roto baler, two corn drill, 8 ft disc, double disc plow, 2 bottom 14" flat bottom plow, and some other things I can not remember.
but all those years I did realize the danger of that snap couple coming un hooked while using a ground engaging tool. so each time I hooked it up I got under there and checked to be sure the pin was hooked proper and the spring was tight on the hook.
as I heard of a man getting hurt bad by the under belly coming unhooked and the plows coming over on him, hitting him before he even knew anything was wrong, was told the family sold all AC tractors, equipment and bought another brand and they had a lot of equipment, but too dangerous for them.
If I still had that type equipment I guess I would attach sometype safety chain from implement to tractor, around the snap couple, as you do when you hook up your trailer to the back of the pickup.
you only get one chance, my friend broke a lower arm on his fergy 3 pt hitch and the bush hog started crawling up the other side tire after him before he got the tractor stopped. accident ruined both rear fenders, ruined the rear tire and scared the you know what out of him.
guess that is why it is so dangerous to let kids drive our old junk tractors.