Solo, mine doesn't do that phenomenom; for whatever reason; maybe it's the XTREME blades. If I'm reading this correctly, then the blades are so loose in the grips that the forward resistance is outweighing the centrifigal force to keep them in alignment at slower rpm's and they push back some out of alignment and flutter. At the higher rpm's, they track correctly with much more centrifigal force. That's just my opinion. You might try adding a tiny bit of weight at the tips, such as tracking tape for decoration.

You can temporarily get them aligned, tighten them and see if the flutter goes away. This would test my theory.

Gary