add extra comments to avoid happening again

superset/config.py

@@ -1078,6 +1078,11 @@ class CeleryConfig:  # pylint: disable=too-few-public-methods
 # It will get executed each time when user open a chart's explore view.
 DATASET_HEALTH_CHECK = None
 
+# -------------------------------------------------------------------
+# *                WARNING:  STOP EDITING  HERE                    *
+# -------------------------------------------------------------------
+# Don't add config values below this line since local configs won't be
+# able to override them.
 if CONFIG_PATH_ENV_VAR in os.environ:
     # Explicitly import config module that is not necessarily in pythonpath; useful
     # for case where app is being executed via pex.

superset/connectors/sqla/models.py

@@ -704,6 +704,8 @@ def data(self) -> Dict[str, Any]:
             data_["fetch_values_predicate"] = self.fetch_values_predicate
             data_["template_params"] = self.template_params
             data_["is_sqllab_view"] = self.is_sqllab_view
+            # Don't return previously populated health check message in case
+            # the health check feature is turned off
             data_["health_check_message"] = (
                 self.health_check_message
                 if config.get("DATASET_HEALTH_CHECK")