Reading the above regarding Smokey.

1. Smokey's time was in the 60's /70's, equipment has come a long way since then;

2. Smokey mentions weights in grams. How would you know the weights? Unless it was disassembled and each part of the rotating assembly weighed!

In Smokey's defense of the above, he's already done the heavy lift and is now discussing maintaining a given balance. (IMHO)

In regards to the balance variable shifting in the rpm range. This is called harmonics and is a college course study in itself! Notwithstanding this fact, it is still far better to make every attempt to cancel out any vibration(s) for added longevity / reiability.