In your case, HW offload can possibly do anything only for IPv6, because that’s bridged/switched. IPv4 has PPPoE as WAN, so it’s regular routing. In case it’s slow, you can try fasttrack, it can speed things up, but I have zero experience with that.
One more thing, with IPv6 bridged, all your devices with IPv6 addresses are accessible from anywhere. I don’t see any problem with that, being accessible is the idea behing public adresses. But usually there’s firewall on router that blocks new incoming connections, which you don’t have now. Still no big deal, since all devices should have own firewalls. So just be aware of that and make sure your devices are configured correctly and don’t open dangerous port to whole world. Alternatively it would be possible to enable bridge IP firewall, but it would interfere even with IPv4 traffic between LAN ports.