I agree. Better not to commit fraud!!
Just get a letter from your FF scheme... or give it a day or two until status updates. You don't need the card if the status is reflected on the BP ... although once the door dragon at an LH wanted to deny me entry to the lounge because my BP showed TG*P (needed to explain this is equal to *A Gold and get her to look up online).
Generally TG will scan your BP which clearly determines whether you're entitled to access. If status is taking a while to update, then I imagine a letter from your FF scheme would suffice.
Forging a letter? Not ethical, I'm afraid.