Ya they are fine as a treat every now and then. There has been some suggestion that it's a bad idea to feed them that all the time because of the high fat content. I am not sure how true that is, but your fine feeding them worms every now and then.
Can somebody tell me do eggs of superworms beatles need moisture t o hatch? I've lots of mites when the humidity of the substrate is wet. I think eggs can dry adn thats why I spray watter. And another question. Are beatles big problem for the young superworms if they have enough food?