The Flex-Able Leftovers album—released on November 10, 1998 on Sony Records—contains five bonus tracks, and is quite different from the original Flex-Able Leftovers Ep.
Unlike Steve Vai’s other albums, which are mostly instrumental, almost all copies of Flex-Able Leftovers feature a Parental Advisory label, as a result of the song Fuck Yourself containing multiple profanities and sexual references.
Other differences from the original version include the recording of live drums on You Didn’t Break It! (the original used a drum machine), and the complete re-editing and mixing of the songs.

The Prophet-5 is an analog synthesizer manufactured by the American company Sequential. It was designed by Dave Smith and John Bowen in 1977, who used microprocessors, then a new technology, to create the first polyphonic synthesizer with fully programmable memory. This allowed users to store sounds, and recall them instantly rather than having to reprogram them manually.
Between 1978 and 1984, about 6,000 units were produced across three revisions. In 1981, Sequential released a 10-voice, double-keyboard version, the Prophet-10. Sequential introduced new versions in 2020, and it has been emulated in software synthesizers and hardware. The Prophet-5 has been widely used in popular music and film soundtracks. 
Before the Prophet-5, synthesizers required users to adjust cables and knobs to change sounds, with no guarantee of exactly recreating a sound. The Prophet-5, with its ability to save sounds to patch memory, facilitated a move from synthesizers creating unpredictable sounds to producing “a standard package of familiar sounds.” According to MusicRadar, the Prophet-5 “changed the world—simple as that.”
The Prophet-5 became a market leader and industry standard. Kraftwerk used it on their 1981 Computer World Tour. David Sylvian used it on Japan’s 1982 hit single Ghosts, and Richard Barbieri—of the same band—has used it frequently. Michael Jackson used it extensively on Thriller (1982), and Madonna used it on Like a Virgin (1984). Peter Gabriel considered the Prophet-5 his “old warhorse” synthesizer, using it for many sounds on his 1986 album So. 
Brad Fiedel used a Prophet-10 to record the soundtrack for The Terminator (1984), and the filmmaker John Carpenter used both the Prophet-5 and Prophet-10 extensively for his soundtracks. The Greek composer Vangelis used the Prophet-5 and the Prophet-10, the latter for example in the soundtrack of Blade Runner (1982).
The Prophet-5 was widely used by 1980s synth pop acts such as Tears for Fears, Devo, Eurythmics, and Soft Cell. Radiohead used the Prophet-5 on their 2000 album Kid A, such as on the song Everything In Its Right Place. Other users include Giorgio Moroder, Tony Banks, Phil Collins, Tangerine Dream, Jean-Michel Jarre, Richard Wright, and Rick Wakeman.