Orphan Killer / Merger
The Orphan Merger utility removes all orphans within the index, joining the sub entry to the main heading, or simply removing the sub heading.
Above, Orphans showing.
Above, Orphans appended.
The Killer utility removes the sub head and appends the page reference to the main heading.
Above, Orphans removed.
All done with one menu action and completely undoable.
InDesign indexing utilities Orphans.