If you need the spirit of the keyword—mobility and low cost—without the legal violations, consider these alternatives.
If you want the spirit of "portable freedom" (using Navisworks anywhere, cheaply), here are the legitimate workflows: autodesk navisworks free freedom portable
Freedom is designed to open NWD and DWF files. Its primary strength lies in handling massive aggregated models that would crash standard CAD software. If you need the spirit of the keyword—mobility
Autodesk has moved to the cloud. With Autodesk BIM 360 Glue or ACC (Autodesk Construction Cloud): autodesk navisworks free freedom portable