The two ATX pins you short to turn the box on connected to the general purpose IO on the pi is probably the obvious play. The pikvm people suggest running all t

The two ATX pins you short to turn the box on connected to the general purpose IO on the pi is probably the obvious play. The pikvm people suggest running all the ATX pins over another ethernet connection which is probably as neat as it'll get, though I'd inevitably connect the ATX-over-RJ45 thing to the switch PoE at some point and that's probably bad with all 8 wires connected. Plus you'd want a ATX header to RJ45-or-whatever port per machine. Workable but not very elegant.