But do you actually need that at the consumer level? Make some properly formatted garbage, send it down the wire to the other end of the tester and see if you

But do you actually need that at the consumer level? Make some properly formatted garbage, send it down the wire to the other end of the tester and see if you can read the result. It won't tell you if the cable is marginal, but how often is that actually an issue? Network cables are connected to hardware that retries, masking such errors.