When our roof was damaged by tree, we had TPO installed.
The shop refused to install roof over the luan ply. They talked with insurance company and agree on price. Insurnce company waived my deductible.
Shop removed luan, installed 1/4 plywood, used floor seal compound over all the seems prior to installing TPO.
It has sevred us very good over many years. I would recommend TPO!
You can get TPO through many roofing vendors in our rea. Many commercial buildings are using it. Same installation as Dicor product.