The Just In Case system seems more a case of "parallel-firewall" than anti-Firewall, given the whole point is to build a stable retreat away from the PC and their extrasolar empire shenanigans. I'd wager OP is looking for Project Ozma, who are black-budget ops for the Consortium, and may constitute a vast Illuminati-esque conspiracy bent on transhuman domination, depending on how the GM feels. Always felt Ozma and Firewall were a bit like the MJ12 and Delta Green, to be honest.

I mean, Oversight also kind of fits. But they're a PC organization nominally tasked with maintaining stability and the free market economy in the Consortium, kind of a combination of several agencies like the IRS, the Secret Service and the FBI or CIA, since they do intelligence against other polities in the system, and y'know, suffer from the usual intelligence agency budget inflation. But they don't really explicitly handle X-risk issues, and most of their "shadowy-ness" seems focused on handling other Transhuman societies and benefiting the Consortium. Also they're a public organization, everyone knows they exist. Project Ozma, on the other hand, is a codename organization nobody knows much about, composed of private SETI programs bundled up during/after the Fall by the Consortium and then hushed up. All the hard and fast information on them indicates they operate in secret, conducing research and counteracting X-risks (or studying them) for unknown reasons. Firewall and Ozma are aware of each-other, and have butt heads in the past.