In my current build, I am going to just use drawer “guides” and let the drawers (still to be built) slide directly on the plywood shelf. I have a 100-year old sideboard/bar that uses this concept and it is still going strong. Sure, after 100-years you can see some grooves starting to develop on the wooden frames, but nothing to be concerned over. Also used same concept on a Shaker 7-drawer Lingerie Chest.

HorizontalMike