Yes, our extension allows you to configure such complex rules easily. All you need to do is to create a shipping rule with shipping per item after X items and add the matching products in the “Apply to” section. Thus, the extension will validate products that match these rule conditions only. The same feature can be set up per Qty and per 1 unit of weight. Additionally, you can add a surcharge or a discount to the shipping cost, following the same rules instead of overwriting the entire shipping cost.