The management resources the /core-service=server-environment and /host=x/core-service=host-environment resources should expose the set of allowed stability levels. Code like the utility ServerSetupTask in https://github.com/wildfly/wildfly-core/pull/5895 can use that to determine if what they want to do will work.

A task could just try and fail, but how such a failure should be handled might depend on whether the desired stability is available; e.g. if not throw AssumptionViolatedException, while a different failure indicates an error of some kind.