Probably the rosin is just at a lower temperature. Set oil to 275°F instead of 350°F and you'd achieve the same effect, if that's the case. (As you suggest.) O

Probably the rosin is just at a lower temperature. Set oil to 275°F instead of 350°F and you'd achieve the same effect, if that's the case. (As you suggest.) Or if the rosin is creating some kind of impermeable seal (unlikely since it's liquid at this temperature, but let's suppose it chemically reacts with the skin somehow) then you achieve the same thing by wrapping the potato in aluminum foil. That's the whole reason for foil around baked potatoes at steakhouses. The point is, the rosin isn't doing anything special you can't already easily do. There's no special flavor here.