One hour to build up the universe, only to have it shattered. One more hour to get you back to where you were.
I feel your assessment of 30 minutes to build the universe in the purest sense is fair, but I'm not sure it accounts for the additional friction involved. You might be the exception, but humans in general are known to avoid building up the universe, so to speak, if they anticipate an interruption. It takes even more time for the mind to accept that the time is right.
And so, all told, I think two hours is quite reasonable.
I feel your assessment of 30 minutes to build the universe in the purest sense is fair, but I'm not sure it accounts for the additional friction involved. You might be the exception, but humans in general are known to avoid building up the universe, so to speak, if they anticipate an interruption. It takes even more time for the mind to accept that the time is right.
And so, all told, I think two hours is quite reasonable.