How To Create A Custom Fee Field That Is Non Taxable (TAX FREE)

Hello,
 
I have created a Custom Fee Field for Tips as customers Book and Checkout.  The FEE FORMULA works properly but the field is Taxed.  Is there a way to toggle this field as NON Taxable (TAX FREE) or is there a custom FORMULA that could subtract out the additional taxes that this field is generating?
 
Thank You,

Hi Brian

Unfortunately, as of right now, there is no option to allow a custom field TAX FREE as you want.

Tuan