Kownacki really isn't anything special, but he's tough and has a good gas tank though so will likely get the stoppage. It's hard to believe Helenius lost to Washington and Duhaupas, that kind of exposes Kownacki's level.
I think if Helenius be able to control the distance and time his punches well he'll will do it again but i dont like style of hanging hands too low too often ( did it alot against washington ) though he showed some Ali like head movement in the first fight against Kownacki xD