The memo in this link says that to obtain an exemption for a material that material must have scientific evidence and tested proof that it is below the lead limits. The burden of proof is on the "manufacturer" requesting the exemption. So it is back to testing at your expense. While it might avoid testing every item or a sample of items in a lot - it still means that a lab must be certifying your claim and basis for exemption.
Sometimes in government what appears to be flexibility, is authored in such as way as to mean nothing - so that when complaints are made - such as what we are trying to do now - those complaints are met with these equally impossible alternatives. Yes, there is a response, but the response is just as difficult to comply with
We all know that there are items that are absolutely lead free- wood, beeswax, 100% cotton, 100% wool, and on. They know it too. Why should we have to prove it.