It depends on Minecraft's API because this plugin is triggered when a player is doing an action that Minecraft wants the server to know. Opening the chat box/viewing advancements etc are client-side actions.
If you find out that something is possible. Feel free to let us know at github.
Because the client only tells the server "I'm dropping an item" when the player is holding an item.
Please feel free to let us know at Discord or Github so we can make this plugin better!