NO, I thing you misunderstand international trade. Making the UK a tariff free Freeport would return it to being a trading nation, importing and then exporting goods.
Other nations may well impose their own tariffs, most do, but it does not affect the trade advantages of Freeport UK.
The usual problems with a Freeport are:
1. Reduced revenue due to loss of tariff income.
2. Increased consumption of imported goods due to reduced costs.
An increased VAT would both replace this revenue and control discretionary spending.
And it gives the EU a massive problem because of that Irish border.