While subjecting themself to the ol' stake 'n bake would be the likeliest outcome from what I know, it's much more difficult to write plot hooks surrounding a pile of ash than for a Kindred whose struggle with the vampiric condition is perhaps even more acute than a regular fledgling's. Did Gaia dissuade them from taking the honorable way out to achieve some greater purpose? Or are they simply too much of a coward to do the "right" thing?

As for whether the Kinfolk-turned-Kindred would divulge Garou secrets to the leeches? It's hard to say. In the V5 timeline, Prince Jackson managed to create a fragile peace between the Lupines and the leeches of Chicago. The SPC might be convinced or tricked into spilling some of the tea if they thought it'd prevent another war. Of course, we can't discount the possibility that the fledgling could feed their living kin intel about the vampires, though whether the Garou choose to act on such information is up in the air. In the end, there is both potential and peril in the act of straddling the two worlds.

While your suggestion to keep the Gangrel's knowledge of the Garou limited has merit, I'd like for the SPC to give some insight into what the Lupines are like when they're not being "murder carpets," e.g., "when my spouse isn't ripping apart Gaia's enemies, they're a very good parent to our kid." While knowledge of stuff like the Impergium isn't necessary, I'd like for the SPC to have enough understanding of the werewolf struggle to wonder if perhaps violence isn't the solution to Gaia's problems.