It works the same as the "Manned Launches". The computers all know what has to be done from T -4 to Liftoff... The final 10 minute holds are for the people (launch Controllers) to make sure all is ready (fuel, electric, computers etc.) before turning it loose LOL
The manned holds are at T -9 But they actually have 3 - 4 Built-in Holds from 3 days before launch to liftoff....