I just received a quote for installation of vinyl plank flooring over the sheet linoleum in my kitchen and bathroom. The contractor indicated that he will put a 1/4 inch luan underlayment beneath the planks. I searched luan underlayment on the internet and a lot of folks do not recommend it for this type of installation or for any kind of underlayment. The terms greasy, etc. came up and there were many suggestions that plywood would be a better choice. Can someone clue me in on this product?