wcs2228
3
I wanted to do the same to set up my GL-MV1000W as a VPN appliance on my LAN that I can route through selectively, but not constantly and not for all devices.
I was able to do this this years ago with an old Linksys router, running DD-WRT, and switching the default gateway on my PC using the NetSetMan utility.
I think you can set up the GL-MV1000 as a router with WireGuard and connect the WAN ports of both it and your main router directly to 2 ports your Internet modem/router. The LAN subnet would be the same for both and your main router would be the only DHCP server.