I was just wondering with which TPP countries China has a FTA, in order to take advantage of the “backdoor”-thing. Your premise, your subject.
China has agreements with most, and is negotiations with the rest. Only Japan and South Korea -for obvious reasons- will probably never come to fruition.
TPP is just a failed attempt to reign in China’s influence in the region. But it won’t, there’s nothing preventing any partner from importing an unassembled kit from China then exporting the assembled version as “Made IN XXXXX”.