But what if that simple test misses the dud?

Wow, that's a solid idea. I read a trucking magazine article last year about a place in Iowa that did something similar, but they also kept a couple of spare gladhands and air line fuses in their kit. @the_william is right about the OBD2 scanner too. A simple code reader could save a driver from a panic over a minor sensor fault. It's all about that roadside fix that gets you rolling to a proper shop.

I read a piece by a park ranger in the Grand Canyon who said the same thing as your friend Dave. He wrote that after twenty years, he still gets a sense of deep time that feels like a physical weight. It's not just seeing the layers, it's feeling them as a kind of slow, patient record. That quiet your friend mentioned is the whole point.

The POS system too? That's wild lol.

Actually the price of yellow glue was around $30 a gallon in the early 80s. That's like $100 today with inflation. For a big project needing multiple gallons, it really added up fast.