Yeah that is where the story ends for now, the witch doesn't call on you for now.
i mean the mind protection story, after you complete it the rest of lizards story is unlocked. so yeah you should do it! sorry about my wording, if there is something in this game that isn't out yet you should always do it unless its a one time thing and you need it later, like an important plot thing. there isn't any of those but like if there ever is that's the only thing you should avoid!