sometimes adapting a model to have a hole all the way and visible is not practical.  I was modifying another design from makerworld to hang on my multiboard and ran into this issue.  Attaching a new style hanger to the back was the solution.  The slide portion of this is intended to be added to an existing model either in a slicer or CAD program.  It can be joined with an existing model with up to 2 mm of join depth.  The Multiboard wall attachment is printed and screwed to the multiboard wall, with the slide going over it.  There are 1, 2 and 3 hole verions depending on your needs.  They are sized to 25mm x 25mm, 25x50 and 25x75, matching up with Multiboard dimensions.  The slides come in tight (25.6mm, standard (25.65) and loose (25.8mm) versions.  You may have test a few and file down a larger depending on your printer tolerances.