Ahh, there. This makes sense. It seems exceedingly obvious now that you’ve said it, but it wasn’t at all obvious to me before. Not all time travel has to be the same kind of time travel. We could have Tardis-y time travel, and the ribbon time folding-y thing Griffyn612 mentioned and any number of other models, some of which could lead to the closed time loops, others possibly allowing the past to be rewritten. This latter version would be the one which Odin was talking about, and the only one, for sure, that we know about which causes temporal echoes. As a matter of fact, if we incorporate Ms Duck’s point that not every being engaging in time travel will have the same skill or power level, it could be that the differences in such is what results in the ability to change time versus getting stuck in a closed loop.

So to the original question I asked—whether the lack of temporal echoes means that we know Time Travel Harry did not fix Little Chicago—the answer, in my opinion, is no, it does not prove anything because we do not yet know enough about time travel in TDF to know that temporal echoes occur in every situation or what type of time travel would be involved in that particular journey.

Hmm I think it got the word I wanted to be bold in the quote but just in case " lack of temporal echoes means that we know Time Travel Harry did not fix Little Chicago—the answer"
From what I understand from CD that you had to be physically close to the area where the Echoes are coming to feel them or thats what I got from both Molly and Harry saying as soon they got to DR island and felt something wrong....whos to say that FH didn't bridge a gap back to the Past Harry timelime far away enough to hide the Echoes your talking about.
Oh yeah I think the timetravel is possible but it might require like 13 mages that From SF talks about to do a ritual or some major gods like the greaks since we haven't really seen Zeus Pantheon.
oh the bob the skull talking about stealing a car to explain to harry about what the gate keeper does and someone said that could be a JB clues about whats gonna happen...FH steals car and trys to run over PH to give him enough time to fix LC..anyway Bob the skull was from another poster.