The video explains it better than what I can throw into words, but basically what I call the "trigger touch sensor" is the pressure sensor that's on some controllers that allows them to detect if your finger is resting on them. When I refer to "trigger response" I'm talking about the actual physical push on the trigger. VRChat doesn't respect the trigger's physical response over the weird trigger's touch sensor, which isn't always reliable.
Video Demonstration & Explanation: