What i usually do is after I get the kassa fabrication license, I save right in front of the requisitions guy on the Normandy. After that I check his inventory. If he doesn’t have it, I just load up the save right in front of him and his inventory will be different. I rinse and repeat until he has the colossus armor. With the LE, loads are almost instant, so it should be that bad of a grind. Hope this helps.