Not sure how did you do it. If you tried 0.6 then increased the time gradually to 4s you should see the point where the number would be the same regardless do you start a few rotations earlier or later.
If I remember correctly on that video the time is ~1.2s.
Apply it say about 9 rotations to the end read number.
Repeat the spin apply it rotation or 2 late , read the number, it should be close to same (it doesnt mean the ball will drop there).
Use another spin and test same .
After you can try to
shift starting point to match where the ball drops or stop also to compensate for rotor speed difference.
