Hi,
Yes, for the basic wired-router setup you described, that should be fine.
Since your ISP uses DHCP, after connecting the bridged modem to the Beryl AX WAN port, it should normally obtain its WAN address automatically.
If you do not need Wi-Fi, you can disable both the 2.4 GHz and 5 GHz wireless networks under the Wireless settings.
With this configuration, you can use the Beryl AX in a similar way to a Brume 3.
Sorry for the delayed follow-up, and thank you for tagging me. I’ve seen your post and will review the setup in more detail. I’ll follow up with you there shortly.