Consult for structural Gambrel roof renovation

I’m repairing some moisture damage from failed soffits. I have a gambrel roof (24’x31’) Gutting has revealed that the rafters have been cut and a knee wall was put in at the knuckle for roughly half of the length of the house to create closets and a water closet in the loft. This has created the moisture issue as the vents are cut off at the knuckle and not allowing airflow to the attic. Can I replace the knee wall by laminating some 2x6s and carrying the load with posts, and blocking flat between the rafters (purlins?) to keep from shifting/bowing?

More details:

What is the primary purpose of the Gambrel roof renovation? Increase structural integrity
What type of new space do you want to create under the Gambrel roof? Storage area
Are there any specific load-bearing requirements for the new storage area? Medium-duty (e.g., boxed items)