I always sort by headstamp. Even before cleaning them. Every batch I run have always same headstamp. No headstamps mixed in a box. Mostly, as said before, to avoid any 380.
No trimming, no special prep. just being that kind of disciplyned guy. It also helps to identify failures, none yet anyway.
If it helps I don´t change my recipes upon cases, some are slightly milder than others.... telling the truth I don´t see any difference.