I’m happy for industries outside the towns – such large industries would be inaccessible else and wouldn’t need you to haul cargo to the town they’re in.
You often found such businesses outside the towns, it’s just that the towns often grew to enclose them… which is going to happen if you start at 1850 and work forwards and keep growing the towns…
The one thing I want to see is variable load levels (25%, 50%, 75%) in the line instructions, so you can keep the goods flowing, while not having empty wagons moving back and forth.