I designed an optical part once that had to spin at very high RPMs (6000). Even though the part was only a couple inches high, it required 2-plane balancing due to its required asymmetry and because it sat on top of the motor; it was only supported on one side and would have generated a lot of vibration without 2-plane dynamic balancing. (The optical part was attached to an aluminum hub and the balancing was done by removing small amounts of the aluminum.)

I suppose in your case it would depend on how symmetric the spinning shaft is, how much vibrational energy it will create, and whether the support structure can withstand this energy.

Speed is 2500rpm, in our case if we select two planes what would be your selection for each plane.

thanks in advance