That seems like a very useful site. Bookmarked.
I gave these to my D&D group yesterday, and they were a hit.
The only downside was that the varnish wasn’t quite as dry as I had thought. They’d been drying in the open air for a few days, and seemed completely dry to the touch, and it was longer than the “dry time” listed on the can. I packed them all in a gallon-size ziploc bag, where they’ve been sitting for the last 3 weeks (we were supposed to play sooner), and when I took them out they were slightly stuck to each other. A little prying easily got them apart, but it was not quite the look I was going for.
Another minor design consideration for v2, or anyone else making these: there are effectively six orientations for fitting the two halves together such that the pockets align, but with three magnets only 3/6 hold. Empty, it’s easy to put the two sides together, then twist until the magnets align, but loaded with dice you can’t. Unless you look at the magnets (and some suggestions to put a layer of veneer or felt would prevent this entirely), you have only a 50-50 chance of the magnets aligning. I had one friend who kept getting it wrong. One solution to this would be to use 6 magnet pairs, instead of only 3. I had initially not done this, because I thought the alignment pins were important, and wanted to make sure they went through all the layers, which meant that I had three spots for magnets and three spots for pins. Another solution to this might be to paint the sides with colors or patterns that make it more obvious how the two halves should align, instead of all one solid color. A single stripe could do the trick, but other designs might be even more obvious. The goal would be something that people align without consciously thinking about aligning.