While it was primarily available in Japan, Australia, and New Zealand, the 1991 3-CD reissue from Sony Music Australia remains the gold standard for fans seeking a complete, high-quality digital version of this rare collection.
The Bob Dylan Masterpieces 1978 3CD Set in lossless quality is more than just a collection of live tracks; it is a historical corrective. It proves that the "Vegas Era" was not a low point, but a fascinating stylistic detour. It showcases an artist willing to risk alienating his fanbase to chase a specific artistic vision—no matter how bombastic or bizarre.
The 1991 Australian mastering is often preferred by purists for its dynamic range compared to later "loudness-war" remasters.
Listening to the Masterpieces set today, one realizes that Dylan was ahead of the curve. He was deconstructing his own mythology, breaking down the "Protest Singer" image and replacing it with a universal showman aesthetic. The booing that greeted his electric tours in 1966 had turned into a confused silence by 1978, as audiences didn't know what to make of the white-faced cabaret singer.
It sounds like you’re looking for a specific unofficial collection: Bob Dylan Masterpieces 1978 3CD Set in lossless quality (FLAC, ALAC, etc.).