I didn’t say it was more important. MC doesn’t see a need for revealing it until later. And they didn’t have much choice in looking for Harper or not.
As for the puzzle, any help I’d give would just be me noting what’s written in the walkthrough, so I’d suggest that (specifically the “old walkthrough” since that section needs to be updated still in the new walkthrough style). Not entirely sure what you’re referring to with your logic and numbers there, but you may be overcomplicating it