V2-10: Tool Holder + ER11 collets + Nut accuracy

I have inaccuracy issues with the original Tool Holder. First of all, I measured all my tool holders and they are all within 0.02mm tolerance. But:
A) all delivered ER11 collets wobble between 0.1 and 0.2 mm
B) the black nut wobbles between 0.1…0.4 mm
I bought new collets from a different supplier - this accuracy issue is now solved.
What I’m more concerned is the nut - if not balanced it will soon damage the motor bearings…