What to include in a deferral letter if no significant academic achievement is made?

Got deferred by an EA school and made it my ED2, currently writing a deferral letter tho I know 99% it’s not gonna help. I didn’t retake the SAT and my GPA doesn’t change much after applying early, so I have no idea what to include. If I send them a letter just showing how much I’m into the school and some progress my EC, would it look weak? if so, what should I do besides cross finger pray?