@Atomicfryingpan
I'll be short because I'm on my phone and hate typing on that. Variety and flexibility, for me at least, needs to be more than either more health or boost. There is hardly a choice to be made here. So yeah, I think that the astromech offer a lot more choice and flexibilty. It is also easier to include more droids than mod since it only impact 3 ships instead of 21 and raising. Bonus point for it being thematic. Basic "boost" can be generic astromech, more flavorful one unique. I actually don't understand the argument about droids needing to be unique, there is currently 3(?) astromech that anyone can take, why is it unthinkable to make more?