Public Service Announcement: Indeed, the wrong spawn in Forrest Level 2 hardlocks this game from further progression.
However, there is a way around this.
By playing through SmallOwl's Strike Of Twilight 2, https://small-owl.itch.io/strike-of-twilight-2, and due to the way the data between these games seems to interface, doing so retro-unlocks the Hell levels in Strike Of Twilight.
The armor you buy in SOT2 that isn't it 1 does get 'erased', and there are some inventory carry over shenanigans, so there are some frusations, but it's well worth it be able to fully play SOT in my opinion.