Auto-translated
This should depend on the GM's idea for the experience, both as an internal concept and as a form of storytelling, and nothing else. For now, I've sketched out drafts and jotted down all sorts of ideas, plot hooks, and quests, clearly dividing them into two groups for different settings and, accordingly, different mechanics. Plus, there are a few that wouldn't fit into either of them, and very few that would work in both. In one case, the first option would be suitable, and in the other, the second.
Added 1 minute ago
And we also need to remember that in both cases, players can agree with each other on related backstories. This helps justify the first option and provides more freedom for the second, as it was in Vistaria.