For humans, Plastics are the only resource that can be imported/exported via Space Elevator (for UE) or Black Market (for LIS), but not in Stargate or even Star Port.
Being the only resource to be limited to 10,000 import/export quantity, this serves only to increase the amount of clicks someone has to do in order to import/export Plastics.
As such, please allow Plastics to be imported/exported via Stargate and Star Port, in order to take advantage of the larger capacit provided by the 2 latter buildings.
Seems like you read into .94 patch notes before it went out