I do tend to write the errors down, although the problem here was that most of the tiles were walkable and I didn't feel like describing to myself what they looked like on paper. My memory kinda sucks that way. Luckily I can save in every map though, as that's the last change I ever make before releasing games.
I'm sure there will be even more chipset errors in the next chapter, but hopefully I can hammer them all out in one day like I did with chapter 3. I'll most likely have everything ready by next week for the conclusion of my play through :)