This is not the option.

If I have 10 different types of items and want to add different discounts to each group of products. I will need to do a few subtotals, separate groups from single items and add a few "discount products" with different discounts and try to not make a mistake because of this overloaded page. 

 

Another thing is the customer - when he received an invoice he sees the price ot the item and call me saying " I thought you gave me cheaper price than it shows on the incoice" and I have to explain to him that he need either look down the page and see applied discount on whole invoice or check subtotal of the grouped items and check discount over there. And I got another question straight away - " So what is the price of the item than?" 

 

Customers are lazy, the want to see item price on the right, final price with discount included. 

It is especially important if you give a quote on the list of the materials and they compare to the competitors by line... what they see is a higher price straight away. They do not look at subtotal and "discount item" and calculate after the price. It affects business a lot when you cannot provide clear pricing.

Quickbooks in India, France already have this feature. It is simple and works fine. I asked about this feature 5 years ago and nobody even touch this question. I see many questions in your discussion board, but the only advice is to do "discount item"

Sad.