What carries over after Part 1: maps, support, and classes for your next route
Finish one protagonist’s twelve chapters before starting the next route from the beginning. Exploration, support, quests, and Blessings reduce repeated work.
Original video: “Fortune’s Weave: what carries over?”; English gaming channel Jay Dunna. Watch the original
Start the next route from the beginning after clearing Part 1
To bring progress into another route, finish one protagonist’s twelve chapters, then begin another from Chapter 1. Do not immediately advance all four protagonists several chapters each. I started several routes together, then had to select replay chapters on the relevant route and restart from Chapter 1 to use carryover.
Explored maps still require reopening carriage gates
Previously revealed maps, explored locations, and known material yields remain visible on the next route. You can reach later regions faster instead of testing every path again. But even with the map revealed, you must physically reopen gates for the carriage network to work. 
Cai also needs to unlock carriages himself before using them to save travel.
Support accumulates across routes
Support raised between 
Seteth and 
Ninae on the previous route remains after switching, so you can keep building it through different stories. Chapter restarts retain support too. You do not need to rebuild relationships from zero to unlock conversations.
While playing 
Leda, invite 
Theodora and someone you want her to bond with to the same meal. This prepares support for Theodora’s later story.
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Class unlocks carry across routes
Classes unlocked on one route help later stories. Leda’s 
Dancer, along with certifications such as 
Guardian, 
Dragoon, and 
Troubadour, gives future companions more development paths. Completing one route and collecting its unlocks before moving on offers more benefit than leaving several routes half-finished.
Quest completion and Blessing carryover
Most completed side quests and notice-board tasks resolve automatically at the corresponding chapter on the next route, granting EXP and Renown without another trip. Temple golem-hunting quests differ: I could do them personally on both routes rather than having them complete automatically. Check what resolves when entering a chapter before planning your trip.
Temple Blessings carry over too, retaining unlocks and upgrades. The Promised One’s related boons are also shared, and completing more protagonists’ Part 1 stories unlocks higher tiers.
Character levels, EXP, and items remain on their individual routes until they are brought into Part 3.
