Promotions - Dynamic discount on items within the same Promotion

Hi there! 

We are dealing with a business scenario for which we are trying to find a solution.

Let's work with the following assumptions:

We have 3 Items

• Item 100101
  • Weight 2 lb
  • Price  $ 10
• Item 100102
  • Weight 3 lb
  • Price  $ 30
• Item 100103
  • Weight 8 lb
  • Price  $ 20 

We have one Promotion at item level, with those 3 items.
And from the Business side, we want to apply a Discount for each item, based on the weight. Meaning we can have a $1 OFF per pound. 

• Item 100101
  • 2 lb x $ 1 = $2 OFF
  • Discounted price = $10 - $2 = $8
• Item 100102
  
  • 3 lb x $ 1 = $3 OFF
  • Discounted price = $30 - $3 = $17
• Item 100103
  
  • 8 lb x $ 1 = $8 OFF
  • Discounted price = $20 - $8 = $12

I have been trying to override or create a new processor with the logic to accomplish this, but I am not finding an easy way to do it. 
One of the main issues is that the object RedemptionDescription has a list of AffectedEntries, but is has only a decimal SavedAmount, which is just one amount that will be applied to all affected entries (besides is read-only).

public class RedemptionDescription
{
...
        public AffectedEntries AffectedEntries { get; }
        public decimal SavedAmount { get; }
...
}

Another thing I have been looking into is overriding the GetRedemptions, to return multiples RedemptionDescription, one for each item, but is getting quite complex.


Workarounds I can think of:

1. Having one item per promotion
2. Having one promotion at order level 

Any ideas or anyone that has gone trough something similar?