I think the flashback here really needs some sort of bigger hook for it to really tie everything together. Skypia is really a good example, because iirc, it´s how we get the confirmation that Wyper is related to Calagra and the Noland lore with that...which iirc we didn´t necessarily know about until the first chapter of that fb, which made it really cool at the time.
Even the Elbaf flashback gives us the mystery of Haralds death at the castle and eventually God Valley.
The Gunko thing feels a bit too obvious and I already have an idea of how it goes down, it´s just a version of Harald but she doesnt get killed early on, and likely is even more naive about the situation because shes younger.
Also, Gunko kind of has to die since it´s been established through Harald that you can´t be free from contracts permanently at all. But I don´t really think that happens, we end up with
>Nika liberates people from contracts
which will be kind of dumb