Quite an interesting rabbit hole of geography, thanks for that. According to Wikipedia, Zealandia (where New Zealand is) is also an "almost entirely submerged

Quite an interesting rabbit hole of geography, thanks for that. According to Wikipedia, Zealandia (where New Zealand is) is also an "almost entirely submerged mass of continental crust" that's half the size of Australia. And "geologists from New Zealand, New Caledonia, and Australia have concluded that Zealandia fulfills all the requirements to be considered a continent". But that "simplified" map of continental plates shows how much geologists definition of "continent" differs from the usual definition. As you said, central America and the Caribbean are on their own plate. And Asia actually contains land from four "principal" plates (Eurasian, Indian, Arabian, and part of the North American plate), while Europe and most of Asia are together on the Eurasian plate.