For the non O it's not mandatory. But, of course it's always good to have one. First I would contact y'r home insurance if and how long you are covered abroad .
In imm. Korat, they use it already long time for a year extension. Although I (Dutch) still can get an income statement from my Embassy, I still have to fill this in. So I only use, besides my address, only option 2.
My friend called me this morning and could not find much. He thought he sent his healthcare policy but also some paper that you don't have a couple deseases. His doctor had to sign for that. So more I don't know. Good luck ! š¤š