Some useful info: Setting the camera view to Iso when in perspective does NOT set it to an actual isometric view. The camera elevation is wrong. You must select Parallel Projection BEFORE selecting Iso to get an isometric view. If you set up the view in LayOut there is no way to get an isometric view. Setting the camera to Iso gives it the wrong elevation regardless of what projection is used.
Once the view is an actual isometric and in LO, you can set the scale to 1:0.816497 for a 1:1 iso drawing. For a 1:100 iso drawing, set the scale to 1:81.6497. This difference in scale is because LO measures the scale in the image plane, while iso drawings measure the scale along axes going diagonally away from the camera.