I thought that the Vengeance looked too long to be a SSD in the cutscene, but oh well, I guess I was wrong.
 I assume that Jerec's taking control of its construction also explains other features, such as:
 1. It looks like the Vengance has wings back by its engines.
 2. The bridge is sort of a box shape rather than being the "classic" SD bridge shape. 
 You said you think that KDY built it, right? Did KDY build all of the SDs? 
 P.S. Yes, I know what KDY stands for (from The Mandalorian Armor, to be exact).  
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