Modified BPS board
This is the standard, one-sided BPS circuit board
Because the Forney space is square, 2 halves of the BPS board are arranged side-by-side, wired with a few extra connections, and glued with epoxy, which was never considered in the original design. I remember something about "necessity being the mother of invention". It's not something I expect a user or even an experienced installer to attempt, but having done it for this project, it could be a special-order item.