While I'm still tinkering with the last details on the silicone molds for the case, there is progress on the electronics side as I just received my order from JLCPCB, containing 20 mostly-assembled boards for a larger batch of prototypes. I had to rework the layout a bit in order to  move most components on the top side (since this cheap assembly service only allows one-side assembly) but the result looks nice. The missing components are mainly the microcontroller, a few ICs, and most mechanical parts (connectors and buttons). The brand new soldering hot plate I just received should help with that. The only trouble is my order for the OLED display for which shipping is taking longer than usual. I suspect Christmas might be to blame here.