Since Fuuka is still a child in the extra chapter of Suzuka, and it shows that its partway through Kimi no Iru Machi in that chapter too, shouldn't KNIM also be considered a prequel, as it takes placing during those years that Fuuka is still growing up until she shows up again in the final chapter? I mean, if we want to be accurate, it would be Suzuka -> KNIM -> Fuuka timeline wise afterall, and if you want to get nitpicky and say that KNIM has nothing to do with either Suzuka or Fuuka, while true, it can still be argued that since its still the same world and timeline that it should be included.
Maybe instead of wording it as prequel, have it as "related" or "same world" or something.
And yes I know there's a lot of butthurt people who hate KNIM but that doesn't mean we shouldn't be accurate.