If mass warps space and time nonlinearly per relevant confirmations of General Relativity, and there is observable retrocausality and also indefinite causal ord

If mass warps space and time nonlinearly per relevant confirmations of General Relativity, and there is observable retrocausality and also indefinite causal order, is forcing time to be the frame of reference, and to be the constant frame of reference necessary or helpful for the OT problem and otherwise?