You forgot the part about going from China to Japan and the associated costs.
It could be cheaper? Could also be more expensive as well.
In any case, if too many people play that game, then it only raises the tariff on Japan. I wouldn't assume these tariffs are fixed. They seem to be tied to trade deficit. So..
yeah.
No real way around them over time.
Might even piss the US government off if you try that. Which is kind of like playing with fire right now. It's not clear to me that this administration believes in rule of law in the strict sense that everyone adhered to in the past.