You might already have addressed this, but it seems to me that you have an underlying assumption that potential intelligence/optimization power is unbounded. Given what we currently know of the rules of the universe: the speed of light, the second law of thermodynamics, Amdahl's law etc., this does not seem at all obvious to me.

Of course, the true upper limit might be much higher than current human intelligence But if there exists any upper bound, it should influence the "FOOM"-scenario. Then 30 minutes head start would only mean arriving at the upper bound 30 minutes earlier.

You might already have addressed this, but it seems to me that you have an underlying assumption that potential intelligence/optimization power is unbounded. Given what we currently know of the rules of the universe: the speed of light, the second law of thermodynamics, Amdahl's law etc., this does not seem at all obvious to me.

Of course, the true upper limit might be much higher than current human intelligence But if there exists any upper bound, it should influence the "FOOM"-scenario. Then 30 minutes head start would only mean arriving at the upper bound 30 minutes earlier.