The factory may need those resources to grow at some point. Best to stash em away just in case.

Yep, but if you run out of storage space then The Factorio Way™ has always been to use some kind of destruction method - from handgunning a wooden box to using a mod to vaporize it into the ether.

You can’t build chests in space, so there’s very limited buffering or surplus options.

I think the biggest change with space is that it appears that the asteroids are an infinite resource.