Render View it's great for fixed camera angle rendering, but not so handy for creating HDR to be used in virtual world where camera angle is not fixed. So it is important to create HDR map that is evenly lit.
Current workaround is to change camera angle in Blender and then export it to HDR LS. It would be great if camera rotation is built-in in Render View.
You are right that the camera position is locked in HDR Light Studio. But it does support multiple cameras.... so you could set up a few different views and switch between them to test the lighting from different angles.
The reason we don't support moving the cameras in HDR Light Studio, is that it would be tricky to then match it back in your 3D software if you moved it. So the workflow is to match your 3D software by not allowing the camera position to change.