If the Council win the JR, then I'd surmise SISU's only route is either back to the Ricoh on a rental deal, or selling to someone prepared to do that, or liquidate. I can't see how building a new smaller ground for £20m - £30m works financially when the club is already in debt up to its eyeballs and in L1.
If SISU win the JR, then I guess ACL will have to seek alternative funding. If they can find it, I guess the argument is moot, we are still where we are. If they can't, then perhaps administration for ACL beckons. The lease probably ends up back with the Council at that point, although either way as ACL's biggest debtor I think CCC have the whip-hand in the Admin process (much as SISU with CCFC Ltd). So there's still no resolution.
Whether SISU win or lose the JR, I still think there's a long way to go before they get hold of the Ricoh.
The way forward is still (imho) to come back to the Ricoh on a much cheaper rent deal, and negotiate honestly for everything else.
There's still a deal to be done - I'd look at something along the lines of getting half of ACL from the Higgs for £6m, and paying off half of the mortgage for £7m and then taking half of all of the income that ACL generates (match day and other), so effectively getting half of ACL's share of IEC too.
That, in effect, gives you a 16,000 seater ground, built and with income streams already in place, for a cost of around £13m - £14m. Compare that to a new stadium of around that size for £20m - £30m with no income streams in place, situated miles from your key audience, and with a motivated competitor for your main exhibition/concert business right on your doorstep. It's just a thought...