If that option is enabled, any uncovered sort detected during query execution will raise an exception as opposed to the warning which is currently logged. The setting should be disabled by default for now, but e.g. it could be enabled by default in HSEARCH 6 and beyond. Users would typically enable it during testing to spot sort requests not covered by @SortableField nor a custom field bridge (see HSEARCH-2021) more easily. It will also be useful for testing the implementation of HSEARCH-2021.