Well as far as i've seen theres no reason it cant go epic as it scales, seems that items that scales work the same way. considering it has a chance to drop Talon of Vultros scaled version i don't see a reason it wouldn't be able to drop an epic BVB.
[doublepost=1561393388,1561392412][/doublepost]Also from the data i've collected after over 100k boxes. the rings patterns and necks and stuff doesen't scale. however dungeon specific drops scale. but not below the Dungeonspecific level. as in Doomspike stayed at 20. same with evocator's Demon Band stayed at 19 as it used to. Talon of Vultros and Assasin's blade scaled to 19.