Settlement agreements regarding code/zoning enforcement are enforceable and supercede claims covered
The settlement agreement had been entered to resolve earlier litigation when the City of Delray Beach tried to enforce a site plan requirement for the particular use of the property that had been adopted after the use had been well established. While the property owner claimed grandfathering/non-conforming use rights, the City didn't respect those and started enforcement proceedings. These were then dismissed with prejudice in a settlement agreement, as were the property owner's counterclaims including the "non-conforming use" defense.
When there were later disagreement (extensive and long-running, based on the opinion) regarding whether the property owner had complied or was complying, the City sued to enforce the settlement agreement and to enjoin the continued use of the property for the use in question. The trial court granted and 4th approved. The court specifically held that the defense that the use should be considered grandfathered was lost by the adoption of the settlement agreement.
The moral: be careful about what you agree to in a settlement, because you're going to be bound to it.