The code in ObjectNameAddressUtil#toPathAddress is wrong: it must look for the childAddress's submodel, not the address of the registry itself.

The current code fails with the exception:

org.jboss.as.controller._private.OperationFailedRuntimeException: WFLYCTL0071: Duplicate path element 'subsystem' found [ "WFLYCTL0071: Duplicate path element 'subsystem' found" ]