GAS - Set by caller Ability Cost Question

Hello, First time posting.

I have a generic resource attribute that I want to reuse for all of my characters. I have set it to be Add Base and Set by Caller for the data tag that uses my base Resource attribute.

I want to change the magnitude of the Cost but not have it ApplyGameplayEffectSpecToOwner, becuase when that happens it applies the cost right away, and I want it to be ran through Check Ability Cost and Commit Ability Cost.

Does anyone know how to Modify the Class Defaults of a Gameplay Ability Cost, in blueprint to be a variable and then updated to be used by the CommitAbilityCost blueprint?