Well it's completely up to you, if you offer and he takes it then you're good to go. I always offer all my snakes food during shed, and they all take it, but if they didn't I would just wait until the next scheduled feeding. Some snakes find shedding more stressful than others, and will refuse their meal. If you don't want to take the chance of him refusing, you can certainly jut hold off until after his shed. My suggestion, though, if you do decide to offer and he does refuse, give him at least a few days before trying again. Good luck with it!