Do you take an afternoon break? Maybe if he gets a solid nap in the afternoon he will be ready to party?
Most reports are with a PPO BOG if you are out of there by 8:40ish you can go get in line for SDMT and get a ride in - we did this last fall and got 2 rides (and a swap pass!) which was awesome. We did have a SDMT FP as well, which I had planned to switch for something else if we got the breakfast ride in as planned but my DS7 loved it so much he wanted to ride it again later so we kept the FP.
If I were you I would plan a FP as a back up in case you don't get on the ride before rope drop, then switch it to something else if you do