How to add second LAN

Hi all. I have a simple home network like internet > modem > SG115 firewall > switch > home LAN.

In home LAN there is already a wireless mesh in bridge mode. The SG115 acts as the router and DHCP server. All wired and wireless devices work as they should so no issues here.

Current setup is like this:

*Network>WAN Link Manager
Gateway IP 192.168.3.1
Subnet 255.255.255.252

*Network>DNS
Obtain DNS from DHCP

*Network>Interface Port 1
LAN IP 192.168.9.1/24

*Network>Interface Port 2
WAN IP 192.168.3.2/30
Gateway IP 192.168.3.1

I would like to add a Linksys wireless router to SG115 (instead of the switch) and let the Linksys be the DHCP server issuing different IP ranges like 10.0.0.1/24 This means the Linksys will be connected to Interface>Port 3. The wireless devices connected to the Linksys only require internet access and do not have access to local resources. Is this possible and how?

Thanks