Accounting tricks are likely the best option. Buy your offshore supplier, or setup an offshore reseller. Start supplying the components to yourself at a loss, m

Accounting tricks are likely the best option. Buy your offshore supplier, or setup an offshore reseller. Start supplying the components to yourself at a loss, making the cost of that component cheaper when it comes to tariffs or this 85% calculation. Increase profit margins to cover the offshore loss. Send money back offshore as part of some sort of suppliers agreement if you need to balance their books. Even if the gov tells you to stop it, it will have taken them a few years and any fines negotiable since politically they still want you happy enough to keep manufacturing onshore.