Comment by IgorPartola

If you have two uplinks and running OPNSense (saying this as someone that does exactly this), you have a particular setup that you have clearly taken ownership of. If that breaks your experience with standard tech, that is part of what you traded off when you customized your setup as such.

IPv6 is strictly worse for this precisely because it is treated as a second class citizen. If it was the default in all the tutorials and we started naming IPv4 as the legacy protocol developers would know better.