I finally built a true geodesic dome out of Geomag.
I used the website https://www.domerama.com to do the strut length calculations for
a modest sized dome - I needed 165 struts in 4 different lengths.
I used double length Geomag classic bars with 1/4" diameter neodymium magnets as shims. These things are
available in lots of different lengths from about 1 1/2" down to 1/32"
I chose the Krushke geometry for the dome, which gives a flat base. It's a buckyball at this frequency.
The struts I needed:
A shim 1/32 x30
B shim 7/16 x35
C shim 3/4 x80
D shim 7/8 x20
Dome radius 8"
Height 9 1/2"
floor base diameter 15"