I don't think anyone has pointed out the obvious:
A Rendili StarDrives Dreadnought is 600 meters long. That is fully FOUR TIMES the size of the C-90. It will never show up in X-Wing. Even at "cinematic scale" it would look ridiculously off-scale if it was double the size of the CR-90, and even that would be way too big.
Granted I don't work for FFG or LFL/Disney so I can't say for sure, but I think "not gonna happen" is a safe bet.
EDIT: my prediction is that if scum get a huge ship, it will be a Minstrel space yacht (Jabba's ship the Star Jewel is an example) which is 160 meters, on par with CR-90 or Raider. That or an Action IV (Wild Karrde) which is 100 meters. Either one is significantly more "scummy" and the Wild Karrde could come with Mara Jade as a Z-95 pilot.
Edited by FatherTurin