Existence of a counterexample separating universal lifts from naive lifts of cocycles
Determine whether there exists a dual unitary 2-cocycle \hat{\Omega} on a locally compact quantum group G for which a unitary 2-cocycle \hat{\Omega}_u satisfies (\hat{\pi}_{red} \otimes \hat{\pi}_{red})(\hat{\Omega}_u) = \hat{\Omega}, yet twisting the amplified comultiplication on M2(C^*(G)) by \hat{\Omega}_u fails to produce a copy of (C^*(G), \hat{\Delta}_u); equivalently, construct a concrete example demonstrating that admitting a universal lift (as defined via a trivial universal linking C^*-algebra) is strictly stronger than the existence of such \hat{\Omega}_u, or prove these notions coincide.
References
Let us stress that the requirement that \hat{\Omega} admits a universal lift in the sense of Definition \ref{DefUnivLift2Coc} is in principle stronger than merely requiring the existence of a unitary 2-cocycle \hat{\Omega}u satisfying (\hat{\pi}{red}\otimes \hat{\pi}_{red})(\hat{\Omega}_u)=\hat{\Omega}. Indeed, in the latter case it is not clear if twisting the amplified comultiplication of M_2(C*(G)) with \hat{\Omega}_u will lead to a copy of (C*(G),\hat{\Delta}_u). We do not know however of a concrete example illustrating this phenomenon.