Thor, several of my thoughts on your question, not sure if any of them answer it or not.
Long and Triple themselves have difference in take off actions, specifically degree of take off, with long obviously having a higher degree of angle. Take off angles in single leg bounding and triple jump would be more closely related.
Single leg bounding have more relation to triple jump, to what degree would depend on several factors…
Speed of the bounds being the biggest in my opinion.
What single leg bounds provide are…
An opportunity to teach posture, foot contacts, swinging segments
Strength development in terms of elastic and reflexive strength and eccentric strength (which are important also in long jumping)