PPro here. I had a web special award BOS-PHL-MKE that I wanted to SDC to an earlier flight and from T-24 to T-6 could not get the AA app to show available flights, even though it looked wide open. I booked it at 6k, and at T-24, there were a ton of 9k options, even on the flight I wanted. I'm curious to see if being an EXP would've given me more options.

I actually didn't know about the restrictions until I couldn't do it on the web and called into the AA desk, who then told me no can do. It was a trip I cancelled, anyway, and had just wanted to test out my supposed SDC capabilities as a PP.