But if the purpose of the emitted nen is simply to mark the space where you are moving to then the act of teleporting itself does not necessarily require emission nen (at least not by that explanation). I don't think the whole thing has to be about being or not efficient for the most part, a different combination of nens could conceivably work just as well(it would only work differently). With the description you gave there is no particular reason for the marks you described to not be interchangeable with conjured objects. I would argue the main difficulty there is that using a conjured object for the island for example would require a far more specific ability than standard emission (emitters are similar to enhancers in that they abilities are simple and straightforward in general or at don't have to be complicated, conjurers usually have complex rules and vows and are generally limited to conjuring 1 object with abilities). Conjured objects are real things therefore having them on the island would be a sort of risk as they could be damaged.Because you must somehow mark with your aura the place you want to go.
In case of Goreinu, it was trough his gorillas. In case of Leorio, it's the trail his aura has. In case of GI, the whole system is based on location that probably have Nen Marks. Or people you know. And for most of that stuff, having your aura far from your body is one of the basic requirements. Even in the case of Kuroro the teleportation was shown between a space that was limited and since we don't know the extents of that ability it's hard to predict the school used.
Anyway, I take the GI phrase as an example because Ging is one of the Top Nen users in the world and I doubt He would put an inefficient school in charge of that particular task. More knowing that his ability doesn't relate to movement.
As far as I can imagine the only way in which I could conceivably see teleportation being strictly an emission thing would be that whoever is being teleported is actually converted to nen and being carried over a distance. In that particular case teleportation would be the definition of emission at large and no other group could actually do that efficiently (you wouldn't want the nen into which you were converted to lose strength over time lol).


