I really hope this Lumiere has some kind of benefit for her /the duchy (should be since he is the second ml) - I mean nothing against kindhearted spirits but giving away this much for a complete stranger is a bit much, I Don't know what kind of hell he is going through but as second ml he probably gets some kind of happy ending anyway
also I'm kinda asking how sure is her knowledge anyway? with her actions, she is changing the fate of a lot of people, sure things like the spirits' names or the mines won't change, but the fate of people... Yus was on the academy and as anti-social as he was, he has made connections with peoples he hadn't in the original or this Robbie, did he die around this time in her novel too? on the other hand this girl, did she die in the original?