I agree with the general point that as technology improves a singleton becomes more likely. I'm agnostic on whether the control mechanisms I describe would be used by a singleton or by a bunch of actors, and as far as I can tell the character of the control problem is essentially the same in either case.

I wonder -- are you also relatively indifferent between a hard and slow takeoff, given sufficient time before the takeoff to develop ai control theory?

(One of the reasons a hard takeoff seems scarier to me is that it is more likely to lead to a singleton, with a higher probability of locking in bad values.)