Split DME additions

While making my Streets of London Porter I was puzzled by the directions. The kit has 2 packages of DME. They call to add one package immediately and then at 45 minutes to add the other. With What is the reason for doing that with extract? As far as I can tell we are not trying to pull flavor out of the extract like we would with grains. It’s an extract. And I had hops separate so I know it has nothing to do with hop flavors.

Late addition of a portion of the DME will result in a lighter color of the final product. Part of the DME at the begining will increase hop oil isomerization.