For the examples below I am using the following resources:
- Bercot, David W., ed. A Dictionary of Early Christian Beliefs: A Reference Guide to More than 700 Topics Discussed by the Early Church Fathers. Peabody, MA: Hendrickson Publishers, 1998.
- Jones, Andrew, Robert Klesko, Louis St. Hilaire, and Jason Stellman, eds. Catholic Topical Index. Bellingham, WA: Verbum, 2013.
Example !: Here both a reference and a headword are shown. If one chooses Reference, no search section is built on the right and the Lookup goes into a prolonged build - sometimes in seconds, sometimes in minutes.

Example 2: Same example but with Headword selected. Note that there is no icon identifying the Headword. Here both Search and Lookup build quickly.

Example 3: However, in this resource there is no reference entry. However, the headword form behaves as expected ... assuming one expects it to build a simple text search ... ignoring completely that you are dealing with a headword.
