I worked on the ground in SFO for a project last summer and it was fascinating to see how ATC played out. Once the GDP starts, even if the sun is out and fog is gone by 10am, it usually spells doom until at least the early afternoon. The airport is at such high capacity that it takes countless hours to clear out the morning mess. Adding an extra layer, the current WN gates (which are supposed to be temporary until the renovations of T1 are complete and we move into the new B gates) are boxed in by construction on one side and the alley of the A international gates. When the heavies push off of A, it basically restricts all inbound and outbound traffic in the alley until that AC completely clears the alley.