This is rough and quickly thrown together, but, thoughts on something like a web configurable Plyramid ™ corner mounts 
…
https://aaronse.github.io/openscad/aza-plyramid.html … (
Takes a while to load since the page uses OpenScad compiled to WASM ~7.5mb).
Configure whatever num_layers and ply_thickness makes sense for the overall desired height, and material thickness you’re working with…
Ideally, the page would let you render and download .dxf containing each layer, bonus points for automatically tiling shapes ready to CNC. GCode generation would be great too, but, one step at a time…
To minimize slop/pivoting on my uneven sloped garage slab, would likely supplement the Plyramids with wood shims, 3D-printed and/or wedge tiling shims.