edit: And BeagleBoards, but I can get those quickly and easily.
Ah ha! Somehow I came to understand a "controller" board, attached to the BBB, is something other than the main board that the ASIC modules are mounted on.
So, is it a simple matter to remove the KnC stock BBB and add a standard BBB having a 5v barrel connector, a USB port and the RJ45 connector? I assume one can add to the apt source list and get programs for wifi if one has a mind to.
No it would seem you still have it wrong. Each miner comes with a BB plus a custom controller designed and built by KNC. The BB connects to the controller board and the controller board has 4 (6 on some versions) connectors to the individual ASIC boards.
Mercury: BB ----> Custom Controller -----> 1x ASIC board
Saturn: BB ----> Custom Controller -----> 2x ASIC board
Jupiter: BB ----> Custom Controller -----> 4x ASIC board
The BB is black portion mounted upside down in the middle. The rest is a custom KNC design. The board brings up a lot of interesting questions. There are connectors for a second BB on the left. The square on the right is almost certainly an FPGA although KNC blured the model out (a customer could take an unblurred photo). Looks like the BB communicates with the FPGA which acts as a data manager for the individual mining boards.