Agreed. I have run Mark 25s on 12 ft Aluminum boats, of various makes, for many years now. This not something a normal person should do; and if they do, they won’t enjoy it. Between the porpoise effect and the fast-acting steering corrections, you basically have to be a little nuts. You’re only going 30 mph but it feels more like 100. One wrong, split-second move and bad things are going to happen, in the blink of an eye. 14 footers vary a great deal in weight and stability. Some bigger ones would be fine for a Mark 25. On the other hand, I have a Car Topper 14" Grumman that is so light that it’s not much more stable than a 12′.
Long live American manufacturing!