Responses
I'd message the original uploader first to ask if they plan to continue uploading before uploading over them, if they say it's fine or you don't get a reply in a few days then I feel like it's fair to just upload over them since you've reached out to them and tried to ask first. just seems more polite doing it that way.

Is it bad to upload over someone? Like what I mean is I alr bought the sidestory in the official app but the uploader hasnt uploaded that chapter yet here