JT, early in the Blackstone thread, there were two modes of thought expressed relating to flaming knobs.
1. You get what you pay for, it's still a great oven and will still get plenty hot when the knob is at a non flame setting, be happy with what you've got and use it.
2. Ovens should NEVER have flame shooting out of them. This is either a defective product (Blackstone's fault) or damage as a result of poor packaging (again Blackstone's fault). Send it back and have them send you one that doesn't shoot flames.
I am firmly in camp two. Send it back.
Now, back when this discussion was at it's peak, sending it back meant getting the same model oven. These days, you might get another model. In fact, I'm pretty sure the move from a 10 psi regulator to a 5 psi regulator was because of this issue. So far, it's looks like the 5 psi regulator is just as powerful, but I'd like to see more 90 second bakes with the 5 psi model before I sign off on it.