Sounds to me like a "rolling rattling" noise, rather consistent. I am more inclined to think it is tranny. Your TOB should be fully released and not spinning.
So you are saying that it shouldn't be spinning when the clutch is engaged with the flywheel while in gear, tires moving? Cause I can hear it for sure. Its an Hydraulic TOB and I set the air gap per the instructions with the shims. However, once you push the clutch in the air gap goes away and it doesn't "retract" and gain the air gap it sits right on the 3 fingers. I'll post another video