I have not worked with the Nodes because I could not find any reference to them in the books that I am reading right now.
However, recently I skimmed through
Liber Hermetis (Zoller translation, re-published through Project Hindsight) and found some material on it. For example (a chapter on "Concerning The Dangerous Year"):
"It will be fitting for us to consider the Head of the Dragon in a nativity, in what sign it is, whether moveable, fixed or of double body, and in which planet's house, or triplicity or exaltation, [for] at that time the virtue of both the planet and of the sign will be debilitated. Indeed, we find very often that planets having the possibility to cause something, either according to the nativity, or according to the transit of that place, do not produce anything. But if they make some appearance in the Head or in the Tail, they are causers of evil things, especially if they are found retrograde or occidental."
It seems that both the North and South Nodes are considered malefic. I have to note though that based on my conversation with Chris Brennan, it seems that the
Liber Hermetis is mostly a compilation of works by later Hellenistic (and based on the notes in the translation, probably Persian as well) authors. So this may not reflect the early Hellenistic tradition which I follow.
Then there is this particularly confusing and probably (in my opinion) corrupted passage (Part 1, Chapter XVI, "Concerning the Considerations of the Figure"):
"The fifth consideration is that you look to the Head and Tail [of the Dragon], in what places and in what decans they are. The Head, when it is with the benevolent [planets] or with the Sun or Moon or with Mercury, causes harm to the nativity and induces disasters. When the Sun is with the Head or the Tail the father is harmed. But when the Moon is, the mother is destroyed and called ignominious, especially when in the angles. But the Head with Saturn and Mars signifies the same, especially in angles, because the Head, when it is with benevolent [planets] produces good, when with malevolent [planets], however, evil. Similarly, the Tail with Saturn and Mars produces good, when with the other, depraved things. It lays aside their virtue..[lacuna]"
Here it seems that the Head causes evil for all planets, but is contradicted by the later statement that being with benevolent planets cause good things. The Tail is more consistent. The Tail with malefics decrease their malefic influences, making them more balanced, and balance in some of the old Greek philosophies is good. When the Tail is with benefics, it also decreases their benefic influences, making them imbalanced, and imbalance causes evil things.
I don't know what to make of this at the moment. More research is warranted.