Dual PPOE / Russian PPOE?

[admon]

It‘s possible but not within the GL GUI

Second LAN on the WAN1 port - Flint2

I think you can try an alias on this interface (static IP). Additional a static route to the ONT IP via the alias interface i guess. https://openwrt.org/docs/guide-user/network/network_interface_alias It should be configurable via Luci. I did the same with my RPi4 so that i was able to use the single LAN Port also as a WAN port.