Mixed carts

Hi, first of all thanks for the plugin!

Is there a way to keep free shipping applied to the product itself without affecting or being affected by non-free shipping products at cart level?

Right now (On mixed free and non-free shipping porducts carts shipping total) by using different combinations of conditions I can get the product that meets these conditions to either apply it’s free shipping to all cart or to loose it and get counted as another non-free shipping product, but I can’t get it to keep it’s free shipping while charging the shipping cost of the other products in the cart.

Eg: General shipping cost per item = 4 dlls
I can get:
free shipping item= 0 shipping cost
other non-free shipping item= 4 dlls shipping cost
cart total= 0 shipping cost
or
free shipping item= 0 shipping cost
other non-free shipping item= 4 dlls shipping cost
cart total= 8 dlls shipping cost
but not
free shipping item = 0 shipping
other non-free = 4 dlls shipping
cart total shipping total= 4 dlls

Any way to achieve this?
Thanks for your help!
Best Regards,