They do have some conceptual similarities to the Yuuzhan Vong. However, the introduction of the Charon predate the Yuuzhan Vong by around a decade.
While the Vong seem at least vaguely mammalian, the charon were arachid/insects. Also, while the Vong were just from another galaxy (or maybe from the Star Wars galaxy, but exiled) the Charon were from a whole other plane of existence - the aforementioned Otherspace.
Also, while the Vong had some depth, the Charon were just death cultists - no ritualized honor system, pain obsession, or anything like that. They just wanted everything dead, period.
I used them in an old D6 campaign as a kind of bio-tech Borg. But, YMMV. Good luck - anybody familar with the expanded universe will inevetibly compare them with the Vong, and on that count they will come out lacking without some overhauling on your part.
However, like the Vong, that kind of threat really seems to remove the "star wars feel." But that's just me.