I don't share your optimism about "belter" type scenarios. We won't know until we try it, of course, but the general trend appears to be that the more advanced a technology is, the more of an infrastructure you need to support it. Only truly primitive technologies flourish without
dependable contact with distant sources of support and supply, and that's all overhead costs, not productive investment.

Even a hundred years ago (1908), just to pick a round number, industrial societies were already dependent on products, services and materials from the entire planet. It's much worse today. A space colony would be the tip of the spear, replacing even (as we once discussed) a helmet faceplate would require shipment from far away, not local manufacture. The supply chain to a big colony might be maintainable, but it would be very difficult for isolated small family or company ships to get new, say, airlock gaskets. Even going back to the depot for a small but vital item would be extremely expensive.

Bear with me for another quick example. If the Antarctica base runs out of dental filling compund, or needs a replacement pair of prescription contact lenses, they have to be shipped in by jet from thousands of miles away.

Multiply that by a million for our colony. Now, if we had replicator technology...