The best demo would be for a user to jump right in and do it for themselves .
The process is simple > create PP effect > open a display group that contains the rgb channels to place the effect (s) > select drop external effect onto rgb channels
After the effect is placed the user has a complete view of the over all effect in pixel by pixel form and can manipulate the effect at a pixel level .
I am not aware of any sequencer that has this capability .
That is not unique to hls. But, nice that it can do it like the others.One of the many excellent features with HLS is that users can place a large Pixel effect either created with .Png Sequences , HLS effects generator or Nutcracker exports on rgb channels and manipulate them at a pixel level for truly Unique effects .