Objective Reduction and Einstein's simultaneity

How does Penrose’s Objective Reduction (OR) model deal with the problem that wave-function collapse seems to happen simultaneously across a macroscopic quantum system, while simultaneity is relative in Special Relativity? For example, if a massive quantum system such as the proposed microtubule network in Orch OR undergoes a collapse as one single event across a spatial distance, in which reference frame is this collapse supposed to be simultaneous?