Yeah, they seem almost unpredictable. I messed with my layout width some more and wound up with nothing again. Or it would bake to the second canvas but zoomed out to 100% whereas the rest of the layer was at 10%... that and it just takes forever to render out more than three canvases (and it doesn't even work in the end).
The confusion this causes is discouraging, so I guess it's time to take a break. And either completely redesign what I had in mind for level size or just scrap this method entirely.
Or, you know, just not use normal maps. There's got to be a more efficient way to generate this sort of static imagery at runtime though, will just have to figure it out I guess.
Sucks that your computer can't run it, that's pretty weird. I got a 3x2 level working, which I think is more than enough to create a small prototype/demo game in. If I want to do a larger project, I'll just stick to a flat graphical style; it's probably my own fault for trying to make Construct do things it wasn't meant to do. No hard feelings, in the end.