I recently went through the exercise of asking one of the Chinese manufacturers how much it would cost to build me a board (a bit pirate adapter board for ESP3 that does all the voltage conversions to the GPIO pins so you don't burn something out). Board layout & BOM already exist on github. They do 5 boards minimum. Ok, so I figure I can sell the other 4 boards, probably not a big deal. Total's about $400. Then we get to the point where I'm about the pull the trigger and it goes to a page on tariffs and it looks like at least 45% + they want my SSN to give to CBP to collect the tariff. That's a hard "Nope" on sending my SSN to China. So I'm going to give this a look.