The VTK backplot has several limitations making it unsuitable for our plasma cutting application. For instance, there is no event for clicking on a line and returning the line #. Also, there doesn't appear to be any true 2 dimensional (X,Y) visual display. Further, I was able to modify the canon associated with the gcodepackplot so that I had crosshairs instead of a cone.
If I can't get the missing minigl issue resolved, I will most likely have to completely redo my GUI on a different platform such as QTVCP as it seems to have a more comprehensive backplot available. Unfortunately, for me, that is a ton of re-work since nearly all of the custom widgets are different, not to mention python handler file changes, postgui hal changes, and file location / system setup differences. But, hey, good practice, right?