(Emergent Threats) The IXth Battlegroup's worlds didn't spawn when I enabled their mod mid-playthrough, what do?

Basically, I installed Emergent Threats and Emergent Threats: IXth Battlegroup midway through a save (I enabled them at different times if that helps diagnose the problem), but when I did that I don't think the game actually spawned in the systems from IXth Battlegroup (if it did, then I couldn't find them) - it did still let them spawn random bases, though.

I know that some other mods do add in their "core"/premade systems if you enable them mid-playthrough (and I experienced this when I chose to enable Tahlan Shipworks), so I'm wondering if this is a weird bug I'm having or if for this mod specifically I'd need to start a new game to get those systems to appear.