I think the extra comments are either NPC specific (like a "where did he go?") or just extra sound files for the general taunt. Anyway, as far as I know, noone has done a mod that allows you to bind specific taunts/sound files like that.
I know that OJP has an background sound (like vader's breathing) support, but I don't think you want your character just randomly saying things during the game.
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