Ha, yes AM's cult being a fleet based thing would be interesting, have the flag ships of each fleet be the things which can hold her like the world tree does for us with her ships all being on the larger side with few being capable of entering atmosphere, her combat oriented personnel would be good at ship and station boarding and counter boarding actions along with fighter pilots when they aren't working on larger ships, also every one is likely to have highly customised gear as well.
She'd want a tower of her own
somewhere though, because what magus doesn't want a magic tower? I imagine she'd probably get a moon somewhere all to herself (because a moon is more
mystical than a planet) where she can do big projects and just go wild with magitech architecture everywhere, and otherwise she'd just set up a tower or a few in places (like Equinox) where she'd want to maintain long term enclaves for trading of services (magitech manufacturing and maintenance, fortune telling, etc.) for resources, recruits, and gossip on where to find neat things to investigate.
Plus, a large surrounding population of non-followers is likely helpful to the happiness of some of her faithful. Most of them were likely drawn to her cult primarily by the lure of Knowledge, but a lot of them were probably also drawn by suppressed chuuni-ness of their own - dissatisfaction with being just another cog in the machine, the desire to be
special - and that's easier to satisfy when there are lots of "normal" folks around that you can feel
special in comparison to. In the early stages, when they were likely still a secret group who didn't have an ancient spaceship all to themselves, all the regular AdMech tech priests would have been that group of "normal" people, but they've probably been on the run for a while and a big group of "normal" folks
who are trying to hunt you down and kill you just isn't the same. Now, they have the option of being among a population of Verdant cultists and unaligned people who can remind them, by existing and not being hostile, that they are an exclusive club for the worthy. It's not even a matter of having people to look
down on, just a matter of having people to look
around at and think "I am
different from them! That's so cool!"