I read this and though... EEEEEK!
I have a thin skin Waco and I limit myself to 1/4 inch ice. I have seen thick skinned Sea Arks busting laterally through 1 inch. However... it is NOT the size of the hull thickness, it is the thickness and the weight and balance of the boat. If I move slow and if I have to break ice in an emergency, my boat actually breaks thick ice (1/2-3 inches) the ice by ramping up on it and breaking it downward. As such, the thickness of your bow is not as important as balance of your boat, the hight of the transom (for when you boat goes up over the ice) and how light your bow is. Some really long and heavy Sea Arks and other thick hulled boats can not ramp up onto ice and therefore have to laterally break ice... which is insanity with brittle soft aluminum.
My worry with extra plates is that a guy will be tempted to take on thick ice because he has an extra few square feet of steel on the front of his boat. Duck boats are not made for breaking ice. Way dangerous. Even more so for aluminum that gets brittle in deep cold.
My 2 cents... avoid, avoid, avoid. If you have to break ice in an emergency (meaning on the way back from a hunt, not the way out to a hunt), use the ramp up method.
Whenst in the year of our Lord 2012-13 seasonst...
Cans - 2
Ross's - 1
Widgeon - 6
Mallard - 4
Gadwall - 5
Pintail - 4
Delicious Shovelers - 8
Delicious Snow Geese - 4