If you imagine that you can insert your Arduino into a small fixture that holds it down and touches off on the bottom of the digital/analog pins. These pins could be multiplexed to a few BNC connectors and/or header.
Such a thing is known as a “bed of nails test fixture” and is ubiquitous in electronics manufacture.
The pins are spring loaded and known as pogo pins, there are several styles of ends of these pins.
Depending on the size these things cost in excess of £1000.