I thought so too, but I don't see how I was able to use the bit flip method for the other plug-ins, such as Vile Lair, with success. I had considered copying the original esp. file, but as you mentioned, this would cause compatibility issues. However there must be a way since the Unofficial Patches for Battlehorn, Frostcrag, and Knights do not seem to use the original plug-in itself, instead using it as a Master File, which do have have such compatibility issues. I'm just not understanding how and why the bit flip method wouldn't work for Knights, Frostcrag, or Battlehorn, but does for the other official plug-ins. Edit: Well I've figured it out. I duplicated the original .esp file and made my changes to it. Then I proceeded to go into Wrye Bash once I was done and add the original .esp file as a Master.