. The simplest definition is if something is real to us in the fallen reality then it is decoherent, wave collapsed, and local.
that's absolutely false.
Bose-Einstein condensates are observed ((= 'wave collapsed')), physical, and coherent.
your lies are coherent -- because they are at all times out of phase with the truth by the same amount.
coherence is invariant phase difference. that doesn't mean "in phase" it means the phase of the two waves have the same offset, whether that offset is zero or non-zero. ((and per de Broglie both uncollapsed & collapsed states of matter, all matter, is wave-like -- so coherence & decoherence
both are applicable to particle-like and wave-like phenomena))