Could fifth columns pre-position invasion supplies?

Could China use fifth columns and warehouses of dual-use goods to support an invasion?

Warehouse demand and the visibility of goods left unused would restrict the opportunity, while coordination and counterintelligence would complicate fifth-column support.

Taiwan's active trading economy limits how long unusual inventories can sit unnoticed in scarce warehouse space. Any fifth-column network would also operate in an intelligence contest that runs both ways, making reliable coordination and secrecy difficult.