If I ever redo my tile I will insist on the grout line be even with the tile edge. My grandmother's tile was this way and her grout always looked clean as the day it was put in. I don't know how many layers of sealant is on my tile, probably not very many. I have been in some of the new homes being built in the new estate divisions around town. These homes are shortcutted to death. Up to code seems to be the only concern, the rest is if it looks good and new it's fine.