For readers who have read this far and still want a single, actionable solution, here is the mimicking a Sibelius portable link.
The company’s licensing model is built on per-machine activation. Whether you use Sibelius First (free), Sibelius Artist, or Sibelius Ultimate, the software requires a one-time installation process that writes registry keys (on Windows) or installs frameworks (on macOS). Consequently, an official does not exist on Avid’s website. sibelius portable link
Modern "portable" music notation with Sibelius is centered on mobile cross-compatibility and cloud access rather than traditional portable software deployments. For readers who have read this far and