^ Agreed -
Also, think about what you are asking it to do.
WAN1 - router 1 wan side
WAN2 - router 2 wan side
LAN1 - router 1 lan side
LAN2 - router 2 lan side.
You are trying to forward ports from the WAN side of router 1 to the WAN side of router 2. To accomplish this, you've put WAN2 on the same subnet as LAN1.
So, *if* you get this working, now you need to pass through WAN1, LAN1, WAN2, VPN onto LAN2, back out WAN2 to LAN1. But, devices on LAN1 don't know how to talk BACK to LAN2, that is unless you config port forwarding or DMZ on WAN2.
Just.. Don't.