Is there an extension available that can either:
1) Apply automatic discounts or can use discount code to baskets based on the method of shipping, for example local pick up
2) Apply automatic discounts or can use discount code to baskets based on the delivery location
You can offer your customers discounts that apply automatically at checkout and on the cart. You can create a percentage, fixed amount.
The automatic discounts can be given for the products, by creating conditional shipping settings and shipping zones for eligible products.
From your Shopify admin, go to Discounts.
Click Create discount.
Click Automatic discount.
In the Automatic discount section, enter a name for the automatic discount.
Categorize the products into two,
1. Products eligible for automatic discounts and
2. Products not eligible for automatic discounts.
Under the eligible product category, create a shipping zone.
If the zone that added the product is not considered under the chosen zone, then the checkout page will not display any automatic discount option.
Well, the problem is I have all products that require negative shipping rates, meaning if they choose for example a slower shipping method, the system will give discount to certain percentage NOT based on the product price but the shipping method. I wonder if your steps described are enough.