Avoid them all. If you choose to go ahead with one, I would suggest having it done through an attorney using an alias so you will have an attorney client relationship which would bar him from disclosing your name. I would also advise using an attorney in a somewhat distant city to further help keep your identity from being discovered.
You might further help prevent your identity from being disclosed by having the attorney submit it through some doctor so HIPPA laws are applicable.
Should also make sure the contract clearly states that no information from the testing company be disclosed to anyone other than you.
Sounds like a great approach and there probably are endless attorneys out there offering this as a 'standard product'. Here's a fellow's reasonably well thought through DIY approach.....
https://blog.someben.com/2017/11/anonymous-genetic-testing/
Yes, mine was a medically-oriented DNA test performed by Assurex Health and is covered by HIPPA. Did not have any copay. However, in regards to confidentiality and privacy, medical records are being made available to LE when applying for a carry permit. This is disturbing.