How to select the parent network of ovn network

A LXD OVN network can be connected to an existing managed Bridge Network or Physical Network to gain access to the wider network.
I have tried both ways.But I still don’t understand how to make a choice.

Is the network communication performance better if the Physical Network is used?

Who can help me interpret the application scenarios of two different parent networks?

Result should be the same, what matters is that the network you’re connecting to is the same on all servers. Whether that’s through a physical nic (eth0/enpXYZ) or through a physical nic placed into a bridge, doesn’t really make any difference.