I have finished georeferencing an image with no attached coordinate system. I was unsatisfied as the image was not accurately overlayed on the map. The dx/dy & Residual error values are not significantly high indicating that there was no human error in the georeferencing process.

I am trying to re-open the GCP table to add more points, however, I have been unable to find a way to do this. The only solution I can think of is to re-do the georeferencing. Is there a way to re-open the GCP table to add more points?

Version: QGIS 3.6 Operating System: Windows 10