Although this question is similar to this one, it is different because asteroid 2012 XE$_1$$_3$$_3$ has a transitional path between Venus's Lagrangian points L5 point and L3 point, whereas 2013 ND$_1$$_5$ follows a tadpole orbit around the L4 point.
It is following a tadpole orbit around Venus's Lagrangian point L4 and is also a Mercury crosser and an Earth crosser. It comes to within 0.05 AU of Earth periodically and has a diameter in the range of 40 to 100 meters.
Edit: From the example of a tadpole orbit on Wikipedia I got the impression that its orbital plane is perpendicular to that of Venus's orbit around the Sun.
If not, couldn't this be done with 2013 ND$_1$$ _5$, giving it gradually an increasingly larger orbit, and wouldn't this allow to approach Venus more easily ?
On the image above we can see that as the asteroid would approach Venus from L4 with an increasingly growing orbit in a plane perpendicular to the circular path of Venus around the Sun, in the end that orbit could go through both the L1 and L2 points.
Question: Can it be shown with equations and reasoning that a polar orbit around Venus would be the easiest attainable option ?