I think the main reason to separate so they can pupate is because they can be somewhat cannibalistic and the worms will feed on the pupae. I tried raising superworms before and was successful but it seemed to me that they took a longer time until I had worms that were food sized.

Regular meal worms on the other hand were so easy it was ridiculous I kept them in rubbermaid boxes on chicken mash and I didn't do anything with them other then toss in some veggies every few days or so and pull out the pupae when I wanted to start another colony. (which is a good idea if you want worms all of the same size)