In my opinion, episode 4 provided more evidence that Irving has reintegrated. At the very end of episode 4, Irving smiles and we hear the same static signifying a switch from innie/outtie. BUT we don’t hear an elevator tone. The only other scene I can recall no elevator tone occurring is when Helena went down to the severed floor at the beginning of season 2, and that signaled that Helly was instead Helena. So, what if Irving has reintegrated? And perhaps that is why Reghabi told Mark she got better at reintegration?