What factors might make it possible for a rogue wave to be more than twice the height of the two colliding waves?

Maybe if the tide was low, the water level would be lower, so that means the rest of the waves would be significantly smaller compared to the rogue wave.

Two big waves could reinforce each other to make one gigantic one through constructive inference.

Explanation from the Lesson:

the oceanic zone is typically defined as the area of the ocean lying beyond the continental shelf, but operationally is often referred to as beginning where the water depths drop to below 100 meters (328 feet), seaward from the coast to the open ocean.

explanation:

that scientist would be robert hooke