I am a bit confused. If you are doing an OCR trace, I assume you are making editable text? Wouldn't this be able to change the text size in a normal application (Word or Draw)? If you are doing a trace that is not creating editable text, but instead a vector image from a raster image, selecting all nodes in the image and dragging them larger should make the entire image larger. You just have to ensure that you grab all nodes in the image. Maybe I am missing something in the question. Please expound if this isn't what you are looking for.