SISU are within their legal rights to challenge any outcome in court, therefore as much as the council/Wasps think they're being a nuisance, SISU are simply exploring the channels available to them.
Wasps/Council could talk to SISU/CCFC about an agreement to remain at the Ricoh, however they hide behind the appeal in court, which our legal system shows to be fair - as the Chief has suggested Wasps and CCC could easily use a mid-long term rental agreement, with revised terms, as a condition of dropping the legal actions once an agreement has been signed.