Tom, I get what you are saying, but there is another way to think of that
A lot of people say "it was so random, don't worry about getting the pattern exact"
But, there are two possible reasons to actually care about the pattern,,,,,,the most important one is that if no one will tell a modeler what the "spec pattern" is, or how to do that in model form,,,,,,there is no way to even know what "close enough" looks like,,,,,,,they at least need a guideline to even hit "approximate" with
the second reason is that some modelers are not building "any old USAF Phantom",,,,some are trying to model a specific one, say, Ritchie's or Old's, etc,,,,,,,then the pattern matters to try and get it as close as humanly possible, so that two aircraft with known pattern variations can be modeled and the differences noticed in the finished model
either way,,,,,,the method of using "elevated masks" is a skill that can be learned on a Phantom and then used later on Spitfires, Hurricanes or Strike Eagles