So after fixing some bad solder job (hand soldered qfn24 only half worked),  and then fixing some bad circuit design with the help of @mozzwald , and getting the kernel rebuilt with the driver and overlay (credit again to @mozzwald ) we now have a working keyboard. I seem to have got my map reversed, but that's a simple fix 😀

Apologies for the vertical video 🙈 I was too excited to notice.

Time to design a case me thinks....