I've noticed mine will sit at the end of his hide in the S pose but he is just checking things out and not hungry or aggressive. I can even pick up his hide without him striking at me. When he is hungry he'll be out and about looking for food during the day. Mine is about the same age as yours but a little lighter at 297G. I just switched him from frozen thawed large mice every 5 days to frozen thawed 30G rats once a week. If it helps I've also seen that temps affect feeding response greatly. If my temps drop below 90 in his hot hide or less than 70 on the cool side of his enclosure he is less likely to eat (winter in a drafty house was a stressful time to try and figure out why a 6 month old snake wasn't eating).
I would take dakski's advice and give him a few weeks to digest what's in his belly since I've read that overfeeding can lead to faster growth rate but a shorter life expectancy.
Just my 2C