In pfSense, you make VLAN interfaces and then assign them however you like. They work like any other interface at that point.
So you could have VLAN tag 01 and VLAN tag 02 setup in pfSense, and assign VLAN 01 as LAN, and VLAN 02 as OPT1.
It's not recommended to mix tagged and untagged traffic on a single interface though, so if your "LAN" interface is plugged into the tagged/trunk port on the switch, it should only use VLAN-tagged interfaces there.