AMEX does a soft pull every month on the day your statement closes. While "Credit Secure" only supplies a crappy PLUS score, AMEX has a FICO every month when they soft pull you. If you can get in touch with the credit department, which honestly can be difficult to do as you can only be transferred to them from the customer service number and they work limited hours, they will tell you your score. I have done this on a few occasions to see how much of a difference FICO and PLUS are.
Give it a shot.