As per topic, it’s a running thought.
The idea of Metaliminal storms that they’re random, chaotic and unpredictable. And that if you wish to chase their system-wide bonuses or their additional anomalies you’ll have to go chase storms around the galaxy.
Having them as a Sovereignty Hub upgrade kind of defeats that idea.
That said, did you know Sov Hubs already have other upgrades? You can install your own upgrades for additional anomalies. There even are upgrades for your own system-wide buffs!
Doesn’t this pretty much do what you’re asking for?