As long as your anemone is healthy, feeding him will help him recover from the stress of capture and shipping. He should at very fast. If he take a long time to eat, he will not benifit from feeding but it likely cause detrimental effect on him because he will not be able to digest it. He will regurgitate the food out later.
I don't feed my new anemone until I think they are heathy, then just a little at first to see how hen tolerate it. Once he tolerate feeding I will feed to help him recover. Once I got him to the size I want, and he is healthy I stop feeding. Carpet will always get food from the fish, eat a snail or two and will grab some of the fish.
