I don´t know how the big seed producers do their job....propably not as good as I would aspect.
I´m using a 30$ equipment to get seeds from 2-3 lb within a few minutes.
This wasn´t my invention, but has been refined by me during the years. As far as I remember the information came from one of the late US pepper seed vendors and went through to me be one of the gurus here at THP.
As far as I know the market (you can see it on the seed purity) only a few seed producers know how to process pods very fast and get clean seeds without black seeds, open hulls and pod debris.
So it´s not cheap or gratis to get my answer.
Peter