Thanks in advance.
But suppose we have eth1 with ip address 10.128.0.1/24 with DHCP server and eth2 with ip address 10.128.4.1/24 also with DHCP server.
If you have two different subnets connected to different ports you're beyond the scope of what Quick Set is for.
With that config you'll have to unbridge the ports or you'll be having multiple subnets broadcasting on the same physical layer.
I believe Quickset is for quickly setting a configuration that will be like: A simple NAT router, A simple AP, a device acting as a wireless bridge between networks, A device waiting to bridge networks together.
Local IP is usually defined as the IP address of the Mikrotik device on it's private NAT network