If it matters (which it probably doesn’t), I thought the OP in that thread was a perfectly legitimate question for GQ. It wasn’t being asked, “Are the gold tablets real?”, but rather, “What happened to them?”
The former question would have been GD, but the latter was GQ, IMHO.
In other words, I didn’t get the impression that the thread was intended as Mormon-bashing (or even Mormon-questioning), at least until later.
Other than that, I’m staying out of this. Religious arguments are unwinnable.