Xcode 7.1 adds: "Interface Builder supports enabling Peek & Pop for segues" per <https://developer.apple.com/library/prerelease/watchos/releasenotes/DeveloperTools/RN-Xcode/Chapters/xc7_release_notes.html>
I'm seeing the new "Peek & Pop/Preview & Commit Segues" for some segues, but not others. Where requirements need to be met for this option to appear in IB?