I'd be surprised if the Varese Family Trust found anything wrong with FRANK ZAPPA playing Octandre or any other piece, as the "Publicity" factor would be squarely in their favor. How many of us knew who Varese was until FZ pointed him out?
I remember that Rage & Fury was not approved by the Varese Trust (in the name of composer Friedrich Cerha), so until now it is not published.
Spence Chrislu, December 17, 1998 (on The Rage & The Fury)
"FZ thought it was the best version he'd ever heard.
The reason for it's delay in release is that it's caught up in legal battles (not with the Varese family or anyone directly associated with Varese)."
Gail Zappa, zappa.com, December 2, 2010 (at the Roundhouse)
"All I can say for sure is that I do want to release it with video documentation and sometime near the end of the year—any year."