Product Allocation Profile Revisions - Percentage Only

Is there any way to use the percentage without putting in a pool amount?  My preference would be to have this percentage apply based on what is available instead of a hard coded number.

One of our branches distributes to 30 other branches (stores). Each store enters their own ST orders on a daily/weekly basis. Store managers order what they think they need. When quantities are limited, we want the ability to limit how much is left of remaining stock and split it out by the percentage of sales for each store.