In the seven-grade transshipment book, the biggest cost is not freight but the time and uncertainty of letter-of-credit document examination. The issuing bank checks bills of lading, invoices and insurance line by line, and any discrepancy can stall settlement for days while funds sit halfway.

A digital-yuan smart contract can replace part of that step. Write cargo reached the STS transshipment point (Fujairah or Sohar, say) plus a third-party inspection certificate issued as contract conditions; once an on-chain oracle confirms both events, e-CNY moves automatically from buyer to seller, closing funds and title transfer in the same second. No discrepancy disputes, no T+2 waiting.

This also lightens the bank's load: regulators flag offshore resales as a heightened-scrutiny structure, requiring in principle the same bank and the same currency for one transaction. e-CNY is already same-currency settlement, and every payment on its ledger is traceable and auditable by design — filling the enhanced due diligence box. Rule F7 — lock the discharge port as an STS structure before the credit is opened — can be hard-coded into the contract so the title-transfer path cannot be altered.

The boundary must be clear: the smart contract replaces the examination plus release slice, not the credit opening or the underlying credit line. Large cross-bank or cross-currency deals still follow the original reporting and narration flow. It is a tool, not a shortcut around compliance.