Thanks for the responses.
Yeah, I won't have to be worrying about it for many years. But I like to think I'm planning ahead! Tilting it to the S seems like a good idea. It's actually on a west all. The south wall space is more limited and will be for things I consider more dear than an Agave, like Fascicularia bicolor subsp. canaliculata when I decide to one day plant that out.