I've been pondering a French cleat system for the shop. I plan on using French cleats at 12", 30", 48", 66" and 84" AFF. I'll be using a minimum of two cleats per cabinet so any cabinet is supported by no less than two cleats. Base cabinets will be supported by two cleats plus two Ikea Akurum legs at the front to make under-cabinet cleaning easier. Any two-cleat cabinet can be placed in any one of four positions vertically. Once a cabinet is placed, one single short screw driven through the back and 1/4" under the fixed cleat will prevent a clumsy person (me) from knocking the cabinet off the wall, yet the cabinets can be easily slid right and left for better positioning. The thought is to use LVL strips 1" thick beveled at 45° as an alternative to Baltic birch for the cleats. The cleats will be screwed to the studs using GRK RSS screws for strength. Still working out the details. I can likely buy LVL scraps/left-overs from my favorite local lumber yard to make the cleats at a reasonable price. Given that this isn't fine furniture, the LVL will be strong and quite durable.