Magnetic Universal Keyboard Feet
I wanted to have some feet I could easily add to a ortho48 keyboard.
As I did not have longer screws but did have 8x3 magnets designed it to allow a magnet to firmly fit in the bottom. The ortho48 has screws that stick out the bottom about 1mm so designed it to allow the screw to keep the foot from sliding off and the magnet to just keep it attached.
This could easily be modified to allow a through hole screw or other option such as double sided tape or glue.