It's trying to work out things based on the actual audio data values being received instead of using something that's doing smarter analysis of the audio data (something I need to get around to doing but the simpler mode was decent enough when I made the plug-in which was then merged into the wacup core). Depending on what else might be going on, a zero check might be enough or it needs to be changed with the extreme top/low values being more there if something weird is going on but if it's working for your setup then I'd just stick with it tbqh.
-dro