My grandma's cast iron skillet is the same deal, she never scrubs it clean and that seasoning builds up layer by layer until nothing sticks. Sounds like your wheat paste works the same way, thin coats over time beat one thick rushed job every single time. Rushing just never pays off with stuff like this.

Three dollars and it still kept losing signal at Zilker? That is wild to me. I would have bet money the paid app would crush the free one. Guess GPS does not care what you paid, huh.

Tbh the "loaded it back in and shot the other side" part is the whole trick people use on purpose. You basically invented your own version of a pre-flash or a texture layer without knowing it. Next time try shooting the first pass way under, like -2 stops, so the second pass reads as the main shot and the first one just adds ghosts.