Im looking to do this too and save me from buying a 2.5g switch. Idealy, Primary WAN as LAN4 and Secondary WAN as USB (I have an Android phone as backup). Ill try out the latest ASUS (stable and beta) and Merlin beta firmwares.
Merlin version 386.7_2, 388.1_beta3_rog, and ASUS 300438821617 (no...