Three times now I've had to dig up the rationale for the Wave moving at faster-than-light speeds, rather than the 1C recorded in Survival Margin. Here it is.
These are quotes from an email discussion from Don McKinney, dated November 2010.
Then Don notes that the known timeline can be leveraged to support the accelerated Wave:
Note that this does not fit all our material perfectly. In particular, how to accelerate the Wave to allow Zhodane to do its thing, but then delaying the Wave to give 1248 time to do its thing. A Wave Bubble?
These are quotes from an email discussion from Don McKinney, dated November 2010.
The fixed canon point is that in 1205, the EW crosses the Gvurrdon/Spinward Marches boundary.
That means it enters Gvurrdon in 1074...
It means that Zhdant itself has under 30 years left. How has the Consulate not already collapsed?
Here's what we "need" (?)...
1. The 5FW must occur against a Consulate which knows (only at the very top) that the destruction is coming, but is otherwise intact. Anything less, and the Consulate isn't an opponent for the Imperium.
2. The Imperium cannot know anything is happening within the Consulate outside of odd intelligence which doesn't fit together.
Then Don notes that the known timeline can be leveraged to support the accelerated Wave:
From MT and TNE, combat within the coreward portion of the Consulate starts as early as 1119 (in fact, there are strong arguments that have been made that the adventure in AM4 is part of this).
So, I think [the FTL Wave] better fits our needs
Note that this does not fit all our material perfectly. In particular, how to accelerate the Wave to allow Zhodane to do its thing, but then delaying the Wave to give 1248 time to do its thing. A Wave Bubble?