Is it possible to have the side and back panel of the cabinet to show in plan?
well, easy way - to lost all 2D functions, but you'll get everything in wiremode.
1. You need to open the object you want via "crtl+shift+o"
2. Go to "2D" script.
3. Select all (ctrl+a).
4. Comment all (--> ! <-- mark)
5. write "project2 1,270,1" (more hee -> https://gdl.graphisoft.com/reference-guide/3d-projections-in-2d
6. Save as a new object (after it, you can find it in an embedded library) and place it on the plane
another way i have found to do that is just turn the object into a morph. that way it will show with a lot of detail. (why just not add the ability to show more detail in the object without having to do this??? )
i recommend keeping a copy of the original object in case you want to keep editing.