I don’t see that as a cosmological position – I think it’s misleading to equate the Trinity with one of the emanation cosmologies from the NHL.
From my perspective, the point of the Trinity is exactly about praxis. The Trinity is a way of organising the experiences of praxis. The mystics of the Christian traditions describe quite eloquently that the direct experience of the Divine has taken, for various people over the last two thousand years, these three forms-in-relationship. I don’t think the Trinity is an intellectual exercise in cosmology, it’s the simplest way of organising the experiences of Christian praxis.
It may well be that the Gnostic cosmologies of the second century texts preserved in the NHL are also ways of organising experience, in which case why prefer the Trinity? I think in terms of theological minimalism – the simplest theology that can preserve essential distinctions.
Is the Trinity essential? Maybe not. I’d encourage you to experiment. Practice, practice, practice. Perhaps experience will begin to enliven the Trinity and bring it from a concept to a reality for you… perhaps it won’t.