Craig, thanks for the advice. Both carboys are topped to within 1 inch of the stopper, so I guess I shouldn't worry about excessive oxidation. I'll wait another month and pull another test. If it doesn't change I'll Kmeta at that point.
I joking told my wife I was taking up this hobby to work on my lack of patience. Guess I should start trying to practice what I preach!
Thanks again for the reply.
Edit: saw this on MoreWines site and it confirms what you said:
*Note that the sensitivity-threshold for the standard vertical test kit is around 70 mg/l, but it takes around 30 mg/l to be considered truly done. So, a good rule of thumb is to just wait an extra week or two after the test shows that you are done and that should be sufficient for a true completion.