My own contributions here: I’ve started working on a parametric freecad design for the enclosure, which ought to be able to scale from small to medium to large to even theoretically “full scale” (large plus two small) widths.
The electrical part is pretty straightforward other than sourcing the pogo pin connector, which is custom to framework. But I found this on digikey/JLCPCB, which ought to work in pairs:
(The needed connector is 2 rows of 4 pins, spaced 2mm apart in the “4” direction and 3.5mm apart in the “2” direction.)
I haven’t figured out how to source and mount the magnets yet; on my dev board from framework the magnets quickly came unglued and I noticed that Joseph was using clothespins so I suspect the same happened there as well. So some better mounting mechanism is needed (or maybe just better glue).