The only problem with any of these ideas is that Atlantic can still say "No, we're not releasing that, give us a new STP album"
Atlantic will never agree to releasing a Boxset, or a live album, or a rarities album. Because all those things only appeal to hardcore STP fans and will do 20-30,000 copies max.
Why settle for that when they can force the band to do one more album that will potentially contain 2-3 hit singles that propel it to sales in excess of a million?
The best option is to find a major label they WILL work for, and that WILL stand behind them, and have that label buy out the remainder of the Atlantic contract.
i think what most likely will end up happening, is that it will be settled out of court, and Eric and Scott will just surrender a small percentage of their profits from the forthcoming STP album to Atlantic in exchange for their freedom