If it acts that way you described, it's close enough.

Don't try to get it perfect, as you have seen, even if you get it "perfect", remove it from the holder, put it back, and it will be off again.

Unless you plan on running at extreme speeds, a prop that's close, is plenty close enough.

I have been flying for over 40 years and, to date, I have balances 3 props - and the only reason I did THOSE was because I was sitting in my shop bored, and someone gave me a prop balancer for Xmas a few years earlier.