I would do what you think and will stand behind on your own, before what anyone here or anywhere else thinks or does. You are responsible for your own methods and you know what you can and cannot do. Besides, not many here are as into realistic and quality as you are, as proven over your time here. You are a well organized and disciplined person and will not tolerate what some of these other hacks will tell you they do.
If a fire company is willing to go with any kinda gold leaf vinyl, they are already conceding to inferior products. I would weigh out what you can get away with if things don't fare in your favor. When we do fire apparatus, we still use the real thing. We size, apply 23.5kt and then varnish overtop due to the extreme conditions some of these machines can see...... not to mention the multitude of washings these things go through.
You are definitely right, I am all about quality and I completely agree with you on the gold vinyls. There is only one real gold leaf, and that is real hand laid gold leaf. But unfortunately I would be out of business if I refused to do anything except real gold. I've noticed that real gold leaf is common up north, as are extremely nice and expensive fire trucks. But things just aren't the same (for the most part) the further south you go. It seems like everyone around here asks for "real gold leaf" and then shows me a picture of
Sign Gold. I think this is partly due to a lot of the shops around here that are selling
Sign Gold as real gold leaf, which really annoys me. I've had to come up with ways to serve my customers, compete with these other shops and still be confident I'm giving them a quality product, even if they can't afford or don't want real gold. So if hand laid gold is out of the question I give them the option of Real Gold brand vinyl, or printed reflective gold leaf. I refuse to use
Sign Gold or any of the many variations of the cheap 3 year gold vinyls. The job I'm working on now is re-lettering a fleet due to bad materials that were originally used. One truck has the 3 year R-Tape gold vinyl that has now turned silver and black, and another truck has what appears to be Leo's gold that is now green, wrinkled and sliding and peeling off of the truck. As far as the edge sealing goes, I hate the way it looks. I take the time to go back after it is installed and poke holes and work the trapped air out from around the gold vinyl, but I still don't like the way it looks. It is a much cleaner install without that clear around the edges.