Yeah, I always ended up doing custom bases for each resource, and then tying it all together with trains. It kept things fresh, because main bus designs absolutely suck the fun out of it. A properly organized and optimized train network is truly a marvel to behold. I always avoided going full grid with my trains, simply because I wanted to avoid the exact “micro factory inside of each square” problem you touched on.

I used a grid for my trains, but only to make blueprinting easier. Nothing worse than bringing two tracks from different parts of your base together, only to realize they can’t actually mate because the damned tracks are off by one square (one started on an odd square, another started on an even) and the tracks literally won’t let you bend them into place to meet in the middle. The grid was simply a standardized track length, so I knew my intersections would always meet up cleanly. Basically, I wanted to avoid this problem:

But I also haven’t touched Space Age at all, so maybe trains are an old meta by now.