The KnuKonceptz works fine in 1/0 receptacles. Use ferrules, they save time and money and prevent shorts. The wire is oversized due largely to the wind, it's pretty loose. When twisted an a ferrule put on it, you're good to go!
That's knu on the left in a 1/0 ferrule, anchor 2/0 on the right, both in ferrules. Either way you go, with either wire brand, use ferrules.