I've made enough 1-off designs for specific boards to motivate me into designing a fully parametric mounting plate. The included .stl file is for a Raspberry Pi with 6mm magnets as the mounting method, but you could use screws or glue just as well. The .f3d file can quickly generate similar mounting plates for other symmetrical 4-mounting-point circuit boards.
MakerGeeks pro-HTPLA, 235C.
The example print uses CA glue to secure 6mm magnets as the mounting method.