I have 2x 1Gbps WAN connections and trying to load balance them so that I can achieve 2Gbps nominal. My main router is a ubiquiti UDM-Pro and although it will load balance, it will not exceed the max speed of 1 port (Confirmed by months of support requests and testing). If at all possible, I would like to make the device as transparent as possible for things like Port forwarding, firewall rules, etc.