The Washington system allowed export construction with disclosure

Would the Washington Naval Treaty stop Britain building new 14-inch-gunned capital ships for Chile?

No, but Britain would have to disclose the ships' details, and the United States would object even without a direct prohibition.

The treaty framework did not impose a simple prohibition on a British yard constructing capital ships for Chile. It did, however, require the design and transaction to be reported, exposing the ships' particulars to other signatories. American objections would therefore be diplomatic and strategic rather than an automatic legal veto.