I’m a EE and understand your logic. The issues I’ve encountered with black boxes (BB’s) is with heat/vibration/connectors. Same as almost all electronic devices. BTW, there are analog components in the BB that don’t follow the rules of transistors.
Locate BB’s in cool ambient spots and mount them in rubber with robust, liquid-tight connectors. Also, no tight conductor bends and room to move without stress from either vibration or bending. Wires with long radius bends are best.
However, we lost a BB on a Honda CR 125 recently. Spent a great deal of time removing the potting around the PCB and components to find a broken or overheated component. No luck. This BB had some history before we remounted it using the above logic…
Go to a good KT100 engine guru for more info for your specific engine. The forum is heavy with experience and also opinion not supported by either logic or knowledge.