Loved the idea but didn't have 12mm magnets, so I replaced the 12x3mm magnet cavity with 3 smaller magnet cavities designed for tight press fit.
The 8mm version was designed to be the same or nearly the same size as the original model, but it was created in Fusion 360 because I suck at editing mesh bodies. The 10mm version is simply an enlarged version.
The 8mm version takes 3 6x2mm round magnets.
The 10mm version takes 3 8x3mm round magnets.
Recommend printing just the first 2-3mm to test fit clearance.
Thank you @Frammis for the idea of the color change!
The 3mf files for Mk3S+ and Mk4 have color change added.
The author remixed this model.
Replaced the 12x3mm magnet cavity with 3 smaller magnet cavities designed for tight press fit.
The 8mm version takes 3 6x2mm round magnets.
The 10mm version takes 3 8x3mm round magnets