The SLC-5/05 supports unscheduled message communication over Ethernet using the proprietary A-B "CSPv4" protocol as well as the messaging protocol functions of EtherNet/IP.
It does not, and never will, support I/O functions on Ethernet. It will not command 1794-AENT FLEX adapters over Ethernet.
SLC-5/05 controllers can run 1794 FLEX adapters using Remote I/O (-ASB), ControlNet (-ACN(R)15), or DeviceNet (-ADN).