Fun plugin! Hope development continues :)

The plugin seems to only be aware of who crushed a skull when it's in their inventory while the crush action is performed. When performing a crush while another player's skull is in a box, for example, the Null Crusher message is given, and no scrap is awarded to the crusher - however, they do get Bone Fragments (have "Give items on crush" set to True).

Ideally it could track and award the crusher player when they crush a skull before first moving it to their inventory. Or perhaps the caveat could be added to the plugin's page.