RE ".....How can I trust that my supplier actually did the right tests? Do I just trust that they follow whatever spec (that passes CE) Espressif gave them and

RE ".....How can I trust that my supplier actually did the right tests? Do I just trust that they follow whatever spec (that passes CE) Espressif gave them and that's enough?..." This is a very important point. It is not unknown for products to have completely fake certifications including a fake lab report and fake certificates. What you need to do is ask for certification report and certification certificate. These documents will show the testing lab. It should be accredited to do the test. You need to contact the claimed testing lab and quote the approval number and check all the approval details match . ie the company, product is correct. Could also get a test lab of your choice to review the accreditation documents and product to verify them ( not retesting) just review to check accreditation.