@scottsh the value you enter for queue length is not used when using FQ-CoDel - CoDel is dynamically managing the queue length within each subqueue created for flows.
@Harvy66 is absolutely right, you really don't want to have hyper-threading enabled. You are inducing way more latency, especially with the limiter loaded with flows, than you probably realize. Even if pfSense was on your bare metal, hyper-threading would not be enabled if it were me.