Your post looks to be directed at Allen & Heath Technical Support. The Forum is primarily for peer to peer communication.

For direct Technical Support response, please raise a ticket for your enquiry here:

We are aware of the EtherSound documentation, but there have been at least two users recently who have issues with long cables (70m plus) from approved manufacturers wired to EIA/TIA 568-B standard. The same cable wiring at shorter lengths of 10m have been OK. The cables were tested with Cat5 test boxes, so were not made poorly. Changing nothing other than the wiring standard, the cable-length issues were resolved.

Thus the statement made in the Knowledgebase is based on experience, rather than theory, and we believe it to be correct.