A handful of manufacturers have produced antibody testing. Gen 1 antibody tests are tough because there are varied immune responses, interfereri g substances and well finding the specific antibody.
Without prper validation and vetting you get garbage in and garbage out.
Remember the hiv antibody testing? I do. It took quite some time to develop for accurate results.
So.. do you want results mow, or accurate results.
Both, but you do the best you can do at the moment.
But, if you are aware that there are potential issues with your test tools, you make that known, so that test results are taken with a grain of salt.