I guess I'm the guinea pig for the SPG Amex. I set up a one-time $175 payment to the day care lady. I charge a lot on the card already and have had the same card for years --- so not sure why this would trigger an FR --- but we'll see.
Interestingly, I tried to set up another identical payment for a later date (since its a recurring charge), but it sticks on the processing page forever and never goes through.