Poisonous Concoction as Quest Reward for Shadow (Important for Ruthless Mode)

I was leveling a Shadow in Ruthless to compare the before and after of the reworked Assassin and noticed that leveling as an attack poison archetype Shadow in Ruthless is extra painful, because we don't have a level 12 skill gem with Venom Gyre not being obtainable. So I thought that Poisonous Concoction could be a good addition to the Shadow's Quest Rewards since it fits thematically and helps to fill the gap left by the lack of Venom Gyre.