Hi @Sherma
As you identified, this is currently not supported by LibreNMS. So the solution requires to identify exactly how the SNMP replies from the Cisco device are structured, parse them, split them, and map them to the right DB cell.
Basically, one OID seems to provide multiple values when using a breakout cable. This probably requires deep changes (one OID should create 4 sensors and not only one as today).
If you decide to go for it, you should get in touch here (or in github) with the team to ensure the right solution is found.
Bye