While printing with my matte filaments (not as smooth/elastic as the normal ones), there seems a small chance an excess loop of filament would strangle another at the bottom open. So I made this part to prevent such loops from touching each other.
It should be mounted upon the bottom section of the buffer (as shown in the picture). The required bolts will be longer (about +3 mm) than the original.
Updates
The author remixed this model.
An addon of the original buffer, no change on original models.