[Mark McLeod]

The symptoms generated by the new system under low voltage conditions (momentary dips as well as a dead battery) would be of interest. The effect of low voltage brownout on a maxed out USB power output, various communications types, PWM/Relay/Digital outputs, voltage regulators, peripherals like the pneumatics breakouts, in addition to how the system handles staged shutdown. The shutdown response to a short on the different types of power pins (what doesn't get cut), overloading the power draw of the USB ports, that type of thing.

Ability of software to detect and report or act on these power outages.

How the system responds to the overload of time unconstrained loops and other common rookie programming mistakes - grind to a halt or critical operations take priority.

Easy to write a test program that exercises every I/O at once. Identify limits, e.g. max number of encoders supported, and what happens when you try to go past those limits. Test and verify the limits they've told you the new system has.