Layout guide
Storage is part of the route, not just a destination.
Warehouses and ziplines can make a difficult layout workable, but they should be judged by the route they create, not by a presumed universal throughput number.
Place storage around the bottleneck
Put a warehouse where it shortens the most important recurring handoff. A storage building that adds a detour can make an already busy chain harder to supply.
Use ziplines to cross real constraints
Use a zipline where elevation, water or island separation creates an expensive walk. After placing it, observe route efficiency rather than assuming the connection alone solves supply.