Using an HF at the intermediate, you can select the role as indexer. Its important to note that the difference between the UF and HF is related to how in the HF, all data is passed through Parsing -> Merging -> Typing -> and Index Pipeline queues.
Even though the HF doesnt index, it just passes on, these queues are still touched and metadata is added. So setting the intermediate's as a Indexer will allow you to monitor these queues. The only thing to be aware of is that the Indexing queues will be doing TCP Out, and not writing to disk. Metrics should still be useful for queue troubleshooting.