The goal of gathering all R9 Hair in a single addon was a brilliant idea, but it was carried on poorly, in my opinion. Actually, nearly any of those hair is a duplicate of hair I had installed already - at the time this information was collected - but with a different (wrong) host assigned. That's why I never enabled this optional VX component in my game. Dress scripts were gathered in a single .bs file (for faster loading), so this was different from previous repacks where each hair was packaged separately.
Here's some information which may be useful to other people as well.
The following are R9 hairs from "400 Hair pack" that were missing in my installation, and weren't available on forums anymore. These should be safe to add, without having to worry about conflicts with other legacy R9 addons.
Hair list:
016, 087, 121-122
126, 132, 135-136
139-141, 143-149
152, 161-171
173-190, 201-243
245-249, 251-285
288, 301-307
309-311, 313-321
323, 325-328
330, 332-336
338-353, 355
357-362, 364-390
399-400
When I come across some unique R9 Hair missing, I check this list and extract/ repackage that single hair as a standalone addon (making sure to include the correct dress script). This was the case, for instance, with R9Hair373 used recently for gobman's model Brenda.
I think this topic should be pinned.
P.S.
This could serve as a reference for the daring who 'd want to make a "better" 400 Hair Pack (I mean, more respectful of the correct host numbers).
Or. even better, gather these hairs in a single VX addon. On second thought, this would be better off as a legacy addon repack (so that existing models would'nt need to be changed).