Don't ask me what that task is. All I know is that at this stage a no-world metaphysic is just as likely, or unlikely, as a one- or two-world metaphysic. Or maybe no metaphysic (or a 'no-metaphysic' metaphysic, ha ha). 'The world is and will always remain absolutely other than I' (Day zero).
OK. So what? What follows from that? That we have two problems, two questions. That's where we came in. The existence of a world, and the existence of I. Two unknowns, two absurdities, two surds. According to Wittgenstein in his 1916 Notebooks 'two godheads'.
Note that Wittgenstein doesn't say 'gods'. This has nothing to do with religion. The word 'ultimates' is a possible translation, but to my ear that doesn't sound ultimate enough. I and the world are two 'ultimate ultimates', separated by an unbridgeable gulf that, arguably, forbids even the application of the concept of number. (Number is a second-order concept applying to first-order concepts, according to Frege; to speak of 'two' is necessarily to speak of two F's for some first-order concept F: Two peas in a pod, a tale of two cities, just the two of us.)
Which reminds me:
The essential move of metaphysics the thing that sets it apart from every other form of knowledge or inquiry lies in an attitude of radical doubt or bewilderment in the face of the very existence of the world. The infant’s desperate cry for its mother thus already contains the seed of doubt that will eventually put the world itself into question. That primordial, temporary but necessary separation from what nurtures and protects us is what first allows room for the fatal question mark to slip silently into human consciousness, a question that is no mere abstract idea, but something that will prove urgent and practical: our very sense of what is real.' (Pathways Metaphysics Unit 1)