Nothing is completely present, there is no transcendental signified. Isn’t this above all what deconstruction is asking for and isn’t this a move beyond metaphysics as the metaphysics of presence? Isn’t this precisely a world without ultimate arche that would ground everything else and from which everything would originate, and without terms that are fully present and self-identical?
Something that has become quite plain from this debate is that when you say ‘realist’ (especially when coupled with ‘substance’!) a lot of people immediately hear contained within that term ‘unmediated, full, infallible, rational, foundational presence’ — which is unfortunate… It throws the proverbial baby out with the bathwater somewhat (i.e. it ditches all metaphysics so as to ditch metaphysics qua foundationalism).
The way Levi describes his own relationship with J.D. it would make sense to describe OOO as ‘post-Derridean’ in the sense that the main lessons of his work have been taken on board and are accepted but, some decades after deconstruction first broke onto the scene, is (refreshingly) no longer bound to Derrida’s method, his vocabulary or his goals.