I am near the end of Signalis (I think, based on how long to beat data) and was also stuck in the nowhere map for way longer than I should've. I ran around everywhere looking for the last hexagonal stone for the door and finally had to look up what I missed. I'm not sure how to do spoilers but it ended up being completely obvious what I was overlooking. There was a puzzle that needed some rearranging but I thought I was still missing a piece.