The thing is: if you can output (through highly automated processes) a device that yields even just 1% more energy than it required in production over its lifet

The thing is: if you can output (through highly automated processes) a device that yields even just 1% more energy than it required in production over its lifetime, you have the opportunity for an exponential growth in energy production at your hands. Higher EROI might indicate a steeper growth, but you can achieve the same by just scaling up production.