Pre-Grinding just to clean the last shells?

Hi have read the discussion in the forum about wheter pre-grinding is necessary or not. And I can see the viewpoints of the persons answered to this.
To me, I would personally skip pregrinding without hesitation BUT there is one point why I'm not sure to skip it.
At the moment I use the champion juicer to pregrind. What a like most is that the champion does "pick out" the few left over shells, which didn't go of at winnowing.
This is the only reason why I'm considering pregrinding. I really feel it a good thing to screen the few shell leftovers (I really would like to filter them out of my final product; due to taste).

The other options, like using a peanut butter machine is nice but lacks the screening.

Do any of you guys know a good way to filter the last shells?
This can be with pre-grinding or even an own process step (if existing).

I would appreciate your opinions to the screening issue.

Thanks,
Andy