I have ~~four ~~ three suggestions for improvement to the supply chain design:
-A method for bulk assignment of destinations: it is possible in the current version to assign a single destination to multiple sources but shift clicking several rooms, but no way to do the opposite. If holding a modifier key were to change the direction of assignment (ie. [clicked room ->supplies-> selected rooms] as opposed to [selected rooms ->supply-> clicked room]) user experience of the supply chain system would be greatly improved.
-Mixed storage assignments: currently there is no way to define flex storage without leaving the commodity undefined (which inevitably ends up getting clogged by salvage). A method to define multiple types of storage (for instance, only carbon or gold in these spaces) and/or a method to only allow factory outputs into a space (no salvage) would be very useful tools for building effective production chains.
-Auto-delivery from factory to storage without specifying a supply chain destination: this is the expected behavior, but without setting a destination for storage, factories currently cease production once internal storage fills.