Ultimately, trying to find a happy medium with the 1/4 inch of added rubber. The inflation has to be enough to keep the 1/4 inch rubber in place rather than it wrapping around the tube as does the Mr Tuffy liners do. Was thinking about vulcanizing the rubber to the tire, but added cost. I sure appreciate the input all, it's a mechanics job to find solutions. People treat these rentals in bad ways, just don't want them having to push the rentals home. It's our job to give them a good experience despite them wanting to run intentionally through the goat head patches.
Cheers!!