更新：Marriott 的官方答复，3.5 之前下单的 Point Advance 预订即使没有 attach certificate，在 3.5 之后也会按照旧的积分标准支付。
“[Members can] retain the lower price from the original reservation … The policy for points advance did not change — we are simply sharing that it is easier and helps avoid confusion if the certificate is attached before the categories change.”
