Lever-style handles would theoretically be easier for a Velociraptor to manipulate than round knobs. The downward pressure required aligns better with their natural claw-gripping motion. Round knobs would require a twisting motion that might prove more difficult given their hand orientation.
Yeah, I think in the movie the “knobs” were actually handle types. I don’t think they would have had the leverage to turn knobs without thumbs.
Edit: this site claims that the wrist twisting motion would have been difficult for raptors to do due to the natural orientation of their claws:
https://dino-world.com/could-a-velociraptor-open-a-door-5-17670/