this is a couple years back, i thought i ask regarding your suggestion. I have this setup, but using another device, so i can have a 3rd wan (5g).
all seems to be fine, my question is while the 250 wan2 is on dhcp i have a private ip, assuming this will be double nat, it does show the public static ip on wan2.
on my third party device with the secondary internet circuit, i setup port forwarding to the 250's private ip, disable all IPS on the 3rd party device etc.
i am using traffic shaping rules on the 250 on wan2 to prefer some subnets to use, like my guests, iot etc.
tested with load balancing, no issues at all - showing public static ip's ok.
i know some other models have the 3rd wan capability, be nice if they implemented on the 250.
is there anything else you would recommend? thanks mate.