So, I'm planning on a trip out west in the summer, and then flying back to NYC via LAX on J. It appears I can get a MileSAAver award on the way back, with the A321 flatbeds, but the only option for that at the lower mileage amounts (vs paying ~30k additional miles) is getting to LAX early morning and then taking AA184, leaving 4:30pm and arriving 1am at JFK.

While I want to save the miles, meaning scheduling with the 1/2 day in LA (Flagship Lounge access being the kicker), an earlier arrival in NYC would be preferred.

I've read the wiki, and if I understand correctly, I should be able to SDFC for an earlier LAX-JFK flight if any award space on the flight is available, correct? Does it make a difference as to what type of award is available / the cost of the award when the SDFC is requested? (Currently, next-day LAX-JFK flights are 115k.)