The following commands run on the USG will use the pppoe1 WAN for the two source addresses specified.
configure set firewall modify LOAD_BALANCE rule 2500 action modify set firewall modify LOAD_BALANCE rule 2500 modify table 5 set firewall modify LOAD_BALANCE rule 2500 source address 192.168.0.102 set firewall modify LOAD_BALANCE rule 2500 protocol all set firewall modify LOAD_BALANCE rule 2501 action modify set firewall modify LOAD_BALANCE rule 2501 modify table 5 set firewall modify LOAD_BALANCE rule 2501 source address 192.168.0.115 set firewall modify LOAD_BALANCE rule 2501 protocol all set protocols static table 5 interface-route 0.0.0.0/0 next-hop-interface pppoe1 commit;save;exit