Reopened
I posted this question: Optimal path on the surface of cuboid doesn't visit the same face twice. It was a simple one and someone answered it as a comment. I was planning to expand on the comment and post an answer. This would have been useful for my future reference. However, the question was closed. I'd like to appeal this. Just because its a simple question doesn't mean it can't be useful. The reason says "it doesn't have context". But I feel its completely self-contained and additional context is unnecessary. In any case, I have added it in an edit.