Some licensed versions check in with a Pegasys server periodically. If you're offline or the legacy activation server is down, the installed version may refuse to work. Portable cracks (however legally gray) remove this dependency.
While there are no academic or official white papers specifically written for this exact version of a portable build, here is the context regarding the software and its "portable" status: Software Overview: TMPGEnc Authoring Works 4 Portable TMPGEnc Authoring Works 4.0.9.37
Legally, users are still required to possess a valid license from the official TMPGEnc website to use the software. Some licensed versions check in with a Pegasys