Policy-based routing has a lot of applications in a home lab or home network. It can be used to change the route taken based on the source or destination, and this can be used in multi-WAN or VPN applications to selectively choose traffic to send over one WAN or which traffic to route over a VPN. It can also be used to selectively drop traffic instead of routing it. Having the ability to change some of these routes from Home Assistant makes it possible to control some of these functions from the HA app or via automations.