Primitives - Tile Offset or World Coords?

[Your Computer]

Your perfectionism goes that far, eh? Most people don't worry about that, since room (environment) decorations (e.g. furniture, decals, lighting, etc) cover up any undesired details anyway. Unless you want your map to look empty, then don't worry about it. Plus, i've only seen people complain about "clipping" issues when playing custom stories, never about half a tile going through a wall.