I know I'm not staff and not involved, but may I offer my point of view?
You're both right and you're both wrong.
Orph, yes, it is Treena's body therefore it WOULD be easier than normal.
However, Cap, Orph is right that you are teleporting an absurdly massive amount of matter, both simple rock and the more complex compounds present in human technology and biological entities. I'd think complexity of the matter, as well as distance and the sheer amount would indeed make this cost a great deal of energy, which would limit how far, how often, and how quickly Treena can teleport herself.
IF it is still possible between these two conditions then it would be incredibly taxing upon Treena, honestly to the point where she would find it difficult to even stay conscious, nevermind continue fighting or perform more magic.