So I've mused this for years and asked it on many a forum so I thought I might ask the same here, the question is in the title.

Darth Traya indeed teaches the newly-christened Darth Nihilus how to harness his life-draining gift to radical heights- so effectively infact that Nihilus saps Traya's powers in a calculated double-cross. However as Nihilus greedily consumes entire planets' life energy, the dark side macerates him even faster.
- Star Wars Knights of the Old Republic Campaign Guide

Now this statement can be interpreted numerous ways, the most conservative being that Traya simply taught him the Drain technique and he evolved the technique himself through his own hunger. At face value it does seem to suggest Traya was fully capable of becoming a planet devouring colossus herself but was wise enough to control this technique.

I believe that the wording of this statement is key here; Traya teaches him 'radical heights' of the Drain technique and though this tutorship seems to dead end with Traya being drained herself one could say that the planet devouring was included in this dead end, as it is essentially stated to immediately follow the coup d'etat.

So is the master fully capable of the apprentice's prowess but wise enough not to conjure it or does Nihilus' hunger make him unique due to being a Wound in the Force?

Does Traya have the capacity to devour planets at a whim? What is your interpretation?