I don't think they'll be likely to just hand over answers. I've seen Commanders be on friendly terms with Sirius after doing a bunch of missions for them -- Perhaps this is a route to the inside. Don't Sirius also have permit locked systems? (Not sure on that one.)
It might be the case that the answers are out there, we just need to piece together the clues. The Formidine Rift is our biggest source of information right now, but remember there's also Conflux and Hawking's Gap. I'm going to try tracking down some more sources on the datalogs found in the abandoned settlements, there might be some obvious clue we're missing which could become apparent if we just compare all the data with each other.
Sirius do have some permit locked systems. I have the permits to them, actually. From what I've seen though, this plan, whatever it is, is secretive enough that they aren't going to tell friendly, or even allied, CMDR's about it. There's a lot on Galnet about Siruis' and Core Dynamics' moves, and I think a lot that we've missed.
I don't think that we've actually used the full tools at our disposal in working at solving this mystery. We've been to the Rift, and we've done well there. We've been to the Pleiades, and we've done well there. We've used our scanners, our frame-shift drives, and our cargo-scoops.
But we've almost entirely ignored the politics of it all. The BGS allows us to bring actual political and financial pressure on some of the known entities here. I believe there's a player faction using this tool defensively, to protect the Prism system. But we can use it offensively too. We know there are factions aligned with Core Dynamics. We can pressure them. Sirius Corp is a both a BGS faction and a powerplay faction. We can pressure them. We have the tools to work against their interests. We should be using them.
/edited to add: our biggest source of information might not be out in Conflux or Hawkins Gap, but right under our noses in the bubble. Or right at our fingertips on Galnet.