We had to cancel a HAL cruise in January a couple of weeks before sailing. When we filed the claim online with Travelguard, we had to provide documentation for the cost breakdown of the cancelled cruise, proof it was paid in full, etc. including the dollar amount of any credit to be issued by the airline, cruise line, hotel, etc. We also had to include copies of the cruise line’s cancellation policies. Our claim was researched and paid but they subtracted the future cruise credit dollar amount HAL had promised our travel agent. (Which we later received, but good only through 12/31/22.)
I definitely understand why you want the full amount in cash, since we would have preferred it, too. (Our claim was complicated by our having used a 2020-issued FCC as partial payment.) But even though you don’t consider the FCC total remuneration, it’s possible the insurer might. The HAL cancellation info you’d provide would state what their policy is if you cancel for Covid. The insurance claim adjusters are already well aware anyway that airlines, cruise lines, etc are issuing credits. Maybe it depends on what the fine print of your policy says.
But hopefully Babr’s answer in the post above is more accurate. Maybe you could have a hypothetical conversation with someone at your insurance company to find out if you can decline a future cruise credit offer under their policy and file a full claim since a FCC is not a like-kind refund for the cash you had to pay HAL.