Do I need a "Route" configured for route domain 0?

For management access, I believe there is a default route set, but that is for management traffic. (tmsh list sys management-route)

outgoing: If there is an interface connected, where the network matches the destination, the device will use that interface. (tmsh show net route)

incoming/replies For replies, the device will use: Auto Last Hop. The device will send the reply to the MAC address on the interface where it received the request.

I hope I could help!