Tubes were incorrectly installed in my new Coker bias-ply tubeless tires on my Darrin.
I thought that the first flat tire at a car show, after an hour trip on an expressway, was a fluke.
I got the second flat tire at the 2012 National after pushing my Darrin around 318 turns on the Tail of the Dragon road.
Fooled twice, I yanked all the remaining tubes out.
PROBLEM SOLVED!!!
Additionally, when I purchased DiamondBack radials for my Henry J, the company stated categorically not to put tubes in the tires because they can cause overheating.
4,000 miles later, including old 66 all the way to California, no problems.
I guess it can depend on how much and hard you drive your cars.