> Cat-6A guarantees less cross-talk with more twists, better balancing, and a plastic separator inside the cable to make the cross-talk more regular and thus easier to cancel out.

This isn't quite right. Cat6A guarantees the frequency and therefore effective bandwidth that is available. But it doesn't talk about physical cable type. A common structured cable for Cat6A is U/FTP which has no plastic separator, no outer shield, but rather each pair is wrapped in foil and is actually less tightly twisted than even Cat5e. Anyone can buy U/FTP cable, but to actually be Cat6A it has to be installed correctly and the installation certified to support Cat6A speeds.