Because I don't like the new acrylique base, I decided to make my own version.
First complete creation on FreeCAD
You can put a 3x*1 mm neodyne N52magnet in the central to magnetise the 30 mm base
Place for one magnet of 5x2mm is include in the 40mm version and two place for the 50 mm and 60 mm version.
You can download version of the base with no magnet hole if you prefer.

After modeling my version I realized that it was really close to the work of "Justinfeltmate", here is his link to Cults 3D, so you can choose the version that suits you best
https://cults3d.com/fr/mod%C3%A8le-3d/jeu/bases-for-dropfleet-justinfeltmate