Honestly, I don't know a concrete answer. I will say though that I give them more room because they won't bury themselves a lot like the mealworm beetles. That's why some people give them egg crate too.

I'd say they need more room. But if you want to do large volume production, you can just have a few beetle tubs and every couple weeks or so, combine the bedding in each one and let that bedding sit and put new bedding into the different beetle tubs.

Just a thought, that's what I've been thinking about doing.