Any acidic stop or fixer will remove some of the stain from pyro negatives. This is why water for a stop bath and TF4 are popular with pyro processing. If your print times are that long, which type of process are you printing?
Since PMK induces general stain, along with image stain, you may be blocking a fair amount of U.V. with your film, but I'm not certain. The 200 doesn't build contrast very well. You might consider something more along the lines of Efke 100 and Pyrocat-hd. The stain from pyrocat is in the highlights, shadow values aren't affected like they are with the use of PMK.