Right now the Scum faction has the "Genius" salvaged astromech which costs zero points because it's usually a bad idea to drop a bomb AFTER you move.
That said, it's cool to have the option for a zero-point astromech ... just like Chopper is a zero-point crew card.
If you could make a rebel-only astromech upgrade that costs zero points, what would you want it to be?
Personally, I like the idea of a non-unique astromech that is zero points that lets you suffer one damage to make an emergency boost even if your ship cannot take a normal action due to stress or overlapping an obstacle or bumping a ship ... then flip that card over.
There are plenty of times I'm stuck on an asteroid or bump the edge of an enemy and would HAPPILY suffer a single damage and lose my astromech if it meant that I could make a boost and be in a better position for my attack.