The margin is thinner than the rhetoric
Gold refining is a high-throughput, low-unit-margin business. Fees are quoted in fractions of a percentage point of metal value, so the returns come from volume and utilisation rather than from the act of processing itself. A national policy framed as capturing value through refining is, in gold specifically, capturing a small toll on a large flow.
That does not make it worthless. It does mean the case should be argued on the terms that hold: employment in a technical trade, assay capability retained onshore, and a documented point at which metal enters the formal economy.
Utilisation, not capacity, is the binding number
Installed capacity is easy to announce and difficult to fill. A plant running well below nameplate carries its fixed costs against a fraction of the throughput it was financed for, which pushes it toward accepting parcels with weaker paperwork in order to keep the furnaces busy. That is the failure mode to watch, and it is an economic pressure rather than a moral lapse.
Accredited buyers downstream will not take metal whose origin cannot be evidenced, so a plant that solves utilisation by loosening its intake rules loses the market it was built to serve. Compliant feedstock volume, not tonnes of capacity, is the constraint that determines whether the policy works.
Where the fiscal case is stronger
The more defensible argument for onshore processing is measurement. Metal that passes through an audited domestic facility is weighed, assayed and recorded at a point the revenue authority can inspect, which narrows the long-standing gap between declared production and declared exports. Fiscal visibility is worth considerably more to the state than the refining fee.
For producers, the read-through is simple enough: operators already able to document origin become preferred suppliers to that capacity, on terms set by scarcity of compliant feedstock rather than by plant owners.