I'm still confused. You told me that orthographic maps are not suitable when teaching the concept of volume. But then you said that it's important to follow GSTG - which does not allow for any option except orthographic maps, even when teaching the concept of volume. Which point is more important? Or is it a case-by-case, transcriber-discretion kind of decision?
You also said that your advice (specifically: not using an orthographic map) is specific to the examples you viewed, and that it's best to maintain consistency throughout a transcription. In this textbook, any graphic that would require an orthographic map is being used to teach the concept of volume (and how to calculate it). I know of no instances that were not reflected in the images I provided. Furthermore, using orthographic maps would by default reduce consistency in the book, as there are composite 3D shapes that are not suitable for orthographic maps.
So my interpretation is that orthographic maps are not appropriate for instances requiring volume, and that we need to find an alterative method to portray the graphic for images used to teach volume. Is this an accurate assessment?