> development, testing, and flight qualification, affecting cost, schedule, and risk
These are all a lot easier if you are not worried about mass anymore. Just give all your structures a 3x safety factor like a bridge, and bring extras of anything complicated. Heck bring a mechanic and tools, too.
Of course this is all fantasy, which was the point of this subthread under kordless, in the first place.
EDIT
> Focusing on a point solution like "propulsion" is not even the right kind of question to answer "why not solve this problem with humans?".
To be more clear: I agree with you. I'm just playing the idea of "what if we had much better propulsion." But of course we don't, so in real life, we do need to carefully consider the factors you mention.