Personally, I thought the original factory spacing was too high, not too low, though I admit I play the experimental version more frequently than the standard one. In pak128.Britain-Ex, factory_spacing is set to 2, and to my mind that's about right. Quite a lot of pak128.Britain's "factories" are actually small city shops — pubs, bakeries, markets, and so on. In real life, it's not unusual to have them close to each other, maybe even next door to each other: so an enforced 16-tile separation is not particularly realistic. Without it, only very occasionally will you find that a supplier and consumer are so close together that you can't readily transport goods between them. If that happens, so what? There will be lots of other factories to supply.