This is 3 different options for mounting a Skadis plate on a all metal surface with magnets and a holding lip. I use them to mount on my gunsafes. They hold suprisingly much weigth.

Magnets used are 12mmx2,6mm. Screws used are M5. Because of tight fit I use a long screw to drag the nut into the parts - just like in the Prusa build instructions.

Long_lip_long mounts on the door or side of a gunsafe with rounded edge.

Long_lip_short mounts on the side of a gunsafe with square edge.

Short_lip mounts on the door of a square edge, with little place to hang on.

Included the Fusion360 files so it is possible to adjust them to other magnets and other usecases.

Other models in the picture:

IKEA Skadis board for A1 mini by vellanix - MakerWorld

IKEA Skadis by SMichaud - MakerWorld

Skadis angled cylinder holder, 35-70mm inner diameter Remixed by Walkonwater3D - MakerWorld

Skadis angled organiser 24mm Remixed by Walkonwater3D - MakerWorld