You can’t outsource liability to a random Chinese supplier with no significant presence in US. Small Chinese company will sign whatever agreement you want and promise to do whatever checks you need - and then do absolutely nothing. What are you gonna do if something goes wrong? Sue them in Chinese court? Good luck.

If you want actual compliance, you have to send actual person (that you trust - it’s another big problem as that person can get bribed) in flesh and blood to verify everything and essentially be part of supplier team. That’s the only way.