Originally Posted by flyerCO

While some TSA agents will have issue, technically you can clear into any terminal regardless of if airline can be accessed from it. TSA made this clear a few years ago. However like anything TSA related, it's a ****shoot if agents knows that.

Also, FYI same is true at CDG with 2E K, L, and M access. Although they do try and stop you, they started allowing, especially since food is basically all airside in 2E once past immigration.