There was an illuminating post by KB last September on the question of why iOS Scrivener doesn’t work directly with iCloud. I think the issues he is explaining there would be multiplied in relation to other services like OneDrive. Dropbox is different in that they make available an API that Scrivener can leverage; none of the other Sync services do.
Note, I don’t have any experience of OneDrive … I don’t even consider using iCloud for sync’ing Scrivener projects between my Macs.
Mark