@Paul Mew yep. looking it up pfsense can handle untagged traffic and tagged traffic as configured and I was wrong about whether it could or could not. Though as to it being recommended there are some rather emphatic arguments about not doing it that way as well as not using vlan 1.@Paul Mew
so dual-mode is brocade specific way of having tagged and untagged vlans on the same port. You want 1/1/1 to be dual-mode allowing it to pass untagged vlan1 and tagged vlan40. Basically follow example 1 below in the link below and substitute vlan 40 and 1/1/1 in.
Commscope Technical Content Portal
docs.commscope.com
@Vesalius has provided the deets on how to configure this in the 6450.