thats exactly what i got from your sketch, so that much is clear If the new board kidna hangs off the side too much, we could use those long 0.1mm headers to it would sit above the other parts. like these i have a rough idea of a PCB layout. could maybe use SMD for bypass caps and resistors to keep space down. but once i get a full schematic ill start working. with what i could understand from your sketch i did get this far. clearly not finished. might throw together a mouser BOM as well. im excited for this, and i don't even have a need for somithing like this.