Exclude Shipping Protection from Free Shipping Threshold

[RLBGS]

We recently started using a third party app that allows us to offer customers the option to pay for shipping protection and carbon offsets. 

We have found that adding shipping protection to a cart is counting toward our Free Shipping threshold of $50, such that if a customer orders something for $49.95 and adds shipping protection, it brings their total order value over $50 and we end up paying for shipping. 

Is there a way to exclude certain products - like shipping protection, electronic gift cards, etc - from counting toward a free shipping threshold?