I use Sanja3D's AMS Flipper riser for my P2S and wanted to hang Multiboard from the side of it, but didn't like the french cleat as I'm clumsy AF and kept knocking it off. (https://makerworld.com/en/models/1924371-p2s-riser-ams-flipper?from=search#profileId-2065087)

This version of a multiboard hanger uses a pin to lock it into place so you can't knock the cleat off.  

There are 2 size of pins-- I like the longer one in case I need a tool to pull it out as it can be very tight.  You can scale as needed for tolerances.