It's made, in part, with particle board and the reason for it's expansion and contraction is moisture absorption. End of story.

If you are okay with the same synthetic teak look that Amel's use on the "wood looking" decks, then go for it. (It's not my cup of tea ;^))) )

As for other options, fiberglass works for me. I like our varnished teak grate or flow-through insert over the top (with a hold-down latch).