It'd be very helpful to be able to display only my debuffs, or have the game prioritize showing my debuffs to me on the focus target bar. Sometimes in a fight I have to untarget the boss to do a mechanic, fight an add, or heal somebody, and it's nice to be able to know when I should be getting ready to switch back to reapply debuffs and DoTs, especially on classes with non-rotational DoTs like healers.