Renovating my kitchen and looking for advice on thoughts/experiences on minimum thickness for a 300mm cantilevered “breakfast bar” style cabinet. I’m thinking 15-18mm quality AA grade marine ply to retain character of the place and just checking RE stiffness/flexion. I’ll be simply oiling it. The cabinet is an older pine panelled, 500mm deep x 2400 long (incl overhang top) bench.