Free shipping for certain products, regular shipping for others at the same time

Is it possible to only enable free shipping for certain products and then have other products (that are ordered together with the free shipping ones) still cost the regular shipping price? Seems like this plugin can only either turn the entire cart into free shipping or have the free shipping products cost regular shipping too.

I’m working on a shop that sells a bunch of regular products, each costing € 6 to ship nationally (buying 2 products = € 12 shipping, no idea why it works like that). It also offers cheap, little sample packets that should come with a shipping cost of € 0. With Advanced Free Shipping, it shows free shipping as long as I only add the sample packets in my basket. As soon as a regular product is added, I can choose between free shipping for the entire cart and paying € 12 for shipping, making the sample packet no longer free to ship.
Is it possible to have this show up as free shipping for the samples and € 6 shipping for the regular product? In my example, it would cost € 6 total to ship one basic product and one sample packet.