Through the course of Jack's canon history (and thus before his Bete Noire history), he made frequent visits to a place called the Nexus. These visits began shortly after David saved his life and continued until the end of his canon history, when he was locked up by his father after his failed coup. (He actually returned to the Nexus again after that, but since that conflicts with his Bete Noire history, I'm not integrating much of his Nexus history after his coup, except as noted below.) Jack's forays to the Nexus occurred outside his own universe and timeline; effectively, time stopped when he went to the Nexus and resumed when he returned. Events in the Nexus therefore did not alter his canon history in any particular way. Everything at home happened just as it otherwise would have. He made the same choices, but the Nexus provided him with something of a release valve for all the emotional upheaval at home.
At first he experimented with anonymity--something that hadn't even been an option at home--and spent most of his time either gallivanting around the network or hanging out in one of the local bars. He met a lot of people this way, among them an artificial intelligence by the name of Jemima Intelligentsiya, who saw through his various facades with gleeful and somewhat worrying ease, and thereby became one of his closest friends. She called him out on a lot of his bullshit, which especially helped become more aware of his own misogynist habits.
Jack also became close to one Alexander Georgiou, reincarnated world conqueror. Because Alex was very taken at the time, their relationship was initially platonic. Still, having friends and trusting people was a positive exercise in normalcy for Jack, and Alex in particular offered a degree of understanding and compassion that had been very much lacking from the rest of Jack's life. Eventually, Jack and Alex did start seeing each other, developing a necessarily intermittent but intense relationship, but since that history is intermingled with events after the canon point I used for Bete Noire, Jack will not remember the specifics, just that he and Alex did become much more than friends.
Somewhere along the line, Jack also met Hasibe Ozcelik and Henry Jekyll, separately but at approximately the same time. He met Hasibe while very, very drunk just after the funeral of his lover, Joseph. Finding a surprising amount of commonality between Joseph's relationship with him and Hasibe's relationship with a taken man, Jack opened up to her and became rather protective of her. He then met Henry Jekyll, struck up a quick friendship based on a few marked similarities in woldview, and then discovered Henry was the man Hasi had been talking about. As a friend to both of them, he was a bystander to their relationship and occasional advice-giver for Henry.
This got somewhat more complicated when Hasi also began seeing Edward Hyde. Though initially wary of Hyde, the man's charisma and penchant for self-destructive (or just destructive) hedonism quickly grew on Jack. He became near as attached to Hyde as he was to Henry, deciding that which of them Hasi dated was ultimately none of his business. As Hyde and Hasi's relationship became increasingly unhealthy, Jack continued to believe that Hyde was redeemable, that his more frightening tendencies could be quelled. More than that, he understood why Hasi might find those frightening tendencies so attractive. Of course, it turned out he had no idea how frightening Hyde really was, and by the time he found out (about the abuse and about the fact that Hyde was actually Henry's crazy alter ego...), things were getting bad enough that, shortly thereafter, Hasi had to perform psychic surgery to merge Hyde's personality into Henry's.
Though a little alarmed by the whole debacle, Jack was glad to have his friend back in whatever form. Hasi and Henry moved in together and Jack kept in touch with both of them. He idolized their relationship to a degree; since so many aspects of it mirrored his own interpersonal failures, he thought, if they could make this work, there had to be hope for him too. Unfortunately, the psychic surgery didn't hold; on Henry and Hasi's wedding day several months later, Hyde resurfaced and Hasi was forced to kill him. Jack didn't know quite how to deal with that, or with the implications for his own potential, so he repressed a lot of the subsequent fallout, but that certainly cemented his protectiveness of Hasi.
I'd like to say that, over the past several weeks, Jack has been remembering bits and pieces of his Nexus history in dreams. This was triggered by the stress of other memories rearing their ugly heads, namely fixating on Joseph's death after a messily derailed hookup with Aimery. He won't remember everyone he met in the Nexus; I'll leave that up to mun discretion, as many of the characters he met are also in Baedal. Also, since the memories are somewhat fuzzy and disjointed, they won't necessarily result in the same degree of emotional balance Jack might have achieved if he'd gone into Bete Noire (and subsequently Baedal) with those memories intact. For a while, he'll feel like the memories aren't quite his or aren't quite real. Still, I'm hoping this will let me build off past CR and character development instead of repeating patterns I feel like I've done to death with this character, which has been a problem for me lately.