Like has already been mentioned, much of what is recommended to new keepers (such as a small enclosure size) is not necessarily the only way to do things, it's just the most foolproof way to do things. I'm sure an experienced keeper could set up a 150 gallon aquarium in a way that doesn't upset a BP, but I wouldn't trust someone new to the hobby to do that. IMO it falls into the category of 'if you have to ask if it can be done, you probably aren't experienced enough to do it'.