I agree that getting him on f/t is the best way to go. You won’t have to worry about finding the right prey size or type. I’d suggest starting the transition sooner than later. I start all my snakes on f/t as soon as I get them and they all transitioned within 3-4 months. I feed my snakes a little on heavier side for their first two years and then I scale back their feeding frequency. At 215g I’d offer him a rat pup every 5-7 days or a weaned rat every 7-10 days.