PBR isn't really a service in the sense that it is constantly running or involved in moving packets. Like the firewall "service," it runs once to set up tables in the kernel then the traffic is processed by the standard kernel code.
I guess the point is that PBR is effectively an easier way to create the routing tables, so why would that be an undesirable method in your eyes? If you want to get closer to the metal, you can manually build your routing tables:
I appreciate the link. Ive read through the entirety of PBR readme as well as gateway and table information.
Ive been a public school teacher for over a decade and can imagine the look on a students face when they ask me for help on a math problem and I hand them a textbook. Can you?
I mean the principle is fairly simple with PBR. There is a LuCI app for it, too... basically you'll create two policies:
regular lan > egress via VPN
secondary lan > egress via wan.
PBR makes this pretty easy.
You said earlier that you got errors from PBR... have you specifically asked for a review of your PBR and network configs?
EDIT: I just setup a test router with a VPN and a second lan, then added PBR. Having never read the documentation nor used the service previously, I was able to get it working as desired in about 15 minutes. I'd strongly recommend using PBR.