Well, removing the knock code gives it the chance of the knock on working, but it's still too unreliable, sometimes working but more often requiring many tries over and over before it finally wakes up. I've decided to use a small neodymium magnet attached to the end of a stylus to wake it from its slumber instead, passing it briefly over the quick circle sensor on the center of the left edge of the screen.
That immediately wakes it up each and every time. That'll have to be my workaround for the unreliable knock on implementation, until LG figures out how to correct it.