Imagine when we get citys in the size of a pocketworld. Including 3d-ness from mixed cultures ala Giant trees above and dungeon below. I can see loading and unloading of people as well as structures happen as a adventurer walks through a place.
I don't picture that happening. That would be extremely massive. I am not even sure Rome was that large.
It would certainly be a huge city.
A minor friendly nitpick because this is a topic of mine interest.
Up to the 19th century, cities were
tiny. Ancient Rome during its height had what... 5 kilometres in diameter? 16th century London packed perhaps 100K people into the same space, if not smaller. Both Rome and London would take only a small fraction of the smallest DF pocket world (as far as I can judge the non-defined scale). I can't imagine city the size of a pocket world.
To have sprawled cities, you need cars. Without cars, the population would be packed incredibly dense, and for a large city you'd need population in millions ("large" still being just a couple of kilometres - see 19th century London). Population in millions is unimaginable without industrial revolution because you have to feed the people somehow. All in all, I guess Dwarf Fortress has no other option that to remain reasonably small (the extreme largest city having what... tens of thousands people?). Not because it's historical, but because if you
simulate things like farming and economy, there's no other way.
That was an European perspective, anyway. I have no idea how they fared in 14th century China.