Thank you Mike!
I really like the idea of a IN-12 board. Most likely my next clock would be a Rev6 classic with IN-12, maybe in a few months.If it is still of interest for you at that point, I'll would like to test your design.
But before that, I need to build a case for my Modular Rev3.
I got a board, and updated the library. It should be accurate to a couple of mils (imperial/inch) now. If you downloaded before, do it again - it's the same link. It wasn't off by much, maybe 10 mils at most. I've also ordered a few boards (B5991/IN-12), so if anyone wants one. let me know. The layout includes neon colons, RADAR (RCWL-0516)/PIR, WS2812Ds (through hole RGB) and other front panel stuff (switch, LDR).