100 miles on the highway daily? what do you do exactly. And if thats the case i wouldn't be afraid to do 7k but to be sure id get one analysis with tbn after 5k just to see how fuel and tbn is but metals wouldn't matter in a break in.
Also why ford motorcraft blend. Do you plan on doing only dealership oil changes or just the free one.
If you're worried about ford wss spec there are a lot of good oil that are better and cheaper with the spec like quaker state full syn. Even if it doesn't meet that spec and you have an issue i doubt ford could prove it failed from the oil. Most of the time they just check to see if its sludged or not if it doesn't have a dealer maintenance record.
Also i thought the ecoboost engines used 5w30 while the non turbo ones used 5w-20.