According to a reader on WeChat, some gift cards are currently available at a 25% discount when redeemed with AMEX MR points. The list is below:

Some of these gift cards normally redeem at a 1:1 rate, so with the 25% discount the redemption value becomes 1.33 cpp. Examples include Saks Fifth Ave, Bath & Body Works, West Elm, Ruth's Chris Steak House, Pottery Barn, and Panera Bread. Looking at the list, Saks is probably the most worthwhile option.

Other gift cards, such as Delta, do not normally redeem at a 1:1 rate, so even after the discount the value is still roughly 1:1. Those are not worth redeeming.