no need to partition it off (unles you want to keep two hatchlings in there), also no need for a smaller enclosure.
what makes BPs feel insecure is large open lines of sight, where for example a predator could spot them and attack them from the distance. like a bird of prey or something.
apart from that, no reason to refuse them a large and luxurious enclosure, if you can provide one. Just add enough hides, fake plants and decoration to break these lines of sight. lots of room for creativity here.