you must change only cp_start.
example.
iptables -A CapPort -i ETH02 -j CapPortACL
iptables -t nat -A CapPort -i ETH02 -p tcp –dport 80 -j CapPortHTTP
iptables -t nat -A CapPort -i ETH02 -p tcp –dport 443 -j CapPortHTTPS
iptables -t nat -A CapPort -i ETH02 -p tcp –dport $REMOTEPT -j CapPortGW
iptables -t nat -A CapPort -i ETH02 -p tcp –dport $REMOTESSL -j CapPortGW
insert this line ar bottom of cp_start
iptables -I SYS_INPUT 3 -i ETH02 -p tcp –dport 12080:12083 -j ACCEPT
for enable ETH02
for another interface change 3 with 4.
first interface (ETH01) is enable from web interface.
In web interface you must select for Client Identity only ip address.
I cannot test with vlan but with i think that work.
work only in routed mode.
After change restart captive portal.
In my test ETH00 public IP ETH01-ETH02 captured
bye