The best pairings stay close to Vík or follow the natural South Coast sequence.
For a compact Vík-area cluster, pair Hjörleifshöfði with Reynisfjara, Dyrhólaey, Reynisdrangar, and Reynisfjall. That gives you beach, cliff, sea-stack, mountain, and sandplain perspectives without pretending each stop needs equal time.
For a longer first-time South Coast day, compare it against Skógafoss and Seljalandsfoss before adding it. Those waterfalls are stronger anchors for most travelers. Hjörleifshöfði is the better choice only when you want the day to feel less crowded and more locally specific.
On a 5-Day Iceland Itinerary, the stop is usually easiest when the overnight plan already places you around Vík. On a South Coast Road Trip, it works best as an optional add-on rather than a fixed checkpoint.