Thanks for taking the time to put this together! Had a chance to test it and I'm impressed by how clean everything looks and how everything is grouped together. Escalations and Elusives are properly sized and there are there additional menus for the added items.
With that said, I think Elusives should go to the right side of the screen after Escalations&Bonus missions and I think they should fall under the primary mission's header " The showstopper"in your sample image. They just look off on the left side of the screen, especially when there are lot of them. I don't know if this was a limitation you ran into when adding them to the locations menu.
Also, another thing that would be great, would be if it was possible to group escalations together by making escalations into Livetiles. Livetiles are those where multiple tiles are combined into one and you can flip through them using your mouse or keys. Currently the pack only mostly have level 3s but maybe the author would be more open to adding more if there was less clutter. I'm assuming additional metadata would be used to group them together.