So I just reset chapter 1 to check out that black hole, but then I noticed that Utopioca doen't look that hard to get in to. After trying a bit with the green flowr near by I managed to get in, but it seems it just sends you into part 3 with your part 1 stuff. It seems to have reset my map too though.
Unfortunately it doesn't seem like the you can go anywhere after you get kicked out to Dr. flip-flop's place.
Oh yeah, I was using the Vita version for this.
Edit: I just misread my map. It's all there.