Corridor of fate rerun

Hi! I recently just got back into the game and I’m absolutely SO stuck on lost bloodline, like I’m stuck on the expeditions to be more specific - are they battles there harder than the usual route battles 🫩? But I was wondering if I could do the corridor of fate rerun event/read the story when I’m only half way through my first route of lost bloodline (alkaid)? And also the event guidelines did state that completed stories can be replayed in the chronicle event story section? Does that only apply when the event reruns or all the time?