The Burden of Shadows Chiming Staff interaction

Not sure if this is a bug or intended mechanic, but the unique staff "The Burden of Shadows Chiming Staff" effect where skill gain 1% of damage as chaos damage per 3 life cost only work with non-channel skills, any channel skills that have cost description as "X life per second" would not benefit from the damage gain.

If it is intended to have this effect can the weapon bonus effect description state that please like how the Lich passive description, but if its not intended then can we get that corrected where channeled spells benefit too.