CA,
Nice approach! Unfortunately, some folks don't have that level of visualization.
Sometimes at work, I'll tell a boss something won't fit, as measured, without having to haul it up in the air to see if it does fit. But many times that's what it takes for them to see it for themselves. One job I was on, several white hats, including those from the general contractor and electricians, and my trade (sheet metal) became involved, when, for me it was blatantly obvious the heel of a large elbow would be covering an electrical box. I had to hoist it up on a genie lift and outline the fitting in marker, so they could see it. It cost ~ 10x more to confirm the interference, than to simply move the electrical box a few inches.