This time I agree with much of what you are saying, although I think Albacore is saying the same thing.
Have you ever heard of the fan method for locating the precise location and size of the different elements on the face of an element or elements in the perspective drawing? That is particularly useful when drawing buildings or interiors from plans. Gives the same result as using diagonals for spacing but has an added advantage of not only locating the position but also the size should you wish to take it that far.