To clarify: I was proposing that "Reduced Crew" or "Automation" be a single tech, probably researched in 10% increments up to maybe 50%, then "Full Automation", with it coming in to play only when units are designed. Thus, I can design a normal engine, as currently done, and there's a drop-down which has "Crew Reduction". Even simpler (but since when has Aurora been about simple?) it could be a function of class design: When you design a class, include a "reduced crew" setting as one of the many fields to fill in. It could even be a checkbox: If set, the crew is reduced by the currently researched automation tech. (So, if you're at "Automation 20%", and you check the box, all crew requirements are reduced 20% across the board.)
I think this would have utility for long-term deployment, esp. explorers and scouts. From an RP perspective, I feel sorry for the crews stuck on my sorium harvesters and asteroid miners. My Valdez-class sorium harvesters have crews of 322, and man, that's got to be the most boring duty imaginable.
There may be other benefits to partial automation, such as improved training speeds (fewer people to train, smaller work units that mesh more quickly, plus adaptive systems that learn the crew's habits and self-modify to accommodate them). OTOH, as others note, there could be increased risk of failure in combat from mesons and microwaves, as well as the possibility of hacking automated systems via ECM (ala the new Galactica).
Ultimately, it's just another dial to play with, and let's part of what makes Aurora fun.