Dear Jacob,
Thanks for updating the patch. Mostly LGTM, one minor comment.
```
+ elog(ERROR, "invalid output_plugin_libraries syntax after check_hook?");
```
Per my grep, it is rarely happen to put"?" at the end of elog() message.
Maybe it's OK to say:
invalid list syntax in parameter \"%s\"
Best regards,
Hayato Kuroda
FUJITSU LIMITED