This bug unfortunately still exists.
Here is a vampire I uploaded to the gallery.
http://i.imgur.com/BUYXRUo.png
As you can see, for his dark form I removed all the vampire face details (cracks, veins etc.) and then saved him to the gallery...cause this is what I want him to look like.
But when loading this vampire in CAS again, the game suddenly auto applies the vampire face details to his dark form, which I removed before.
http://i.imgur.com/qlz1BCu.png
On the left you can see the vampire face as I edited it in CAS (removed all the ugly vampire face details) and as I uploaded him to the gallery.
On the right you can see what his dark form looks like after loading him out of my library/ gallery (suddenly he has these vampire face details again).
It actually seems that he always reverts to the dark side vampire face details which he randomly got after his ingame transformation into a vampire before I edited him in CAS. The game obviously doesn't allow to have "no" dark side face details chosen, so it always returns to the veins and cracks etc. which he had directly after his ingame transformation.
This also happens when saving a game with my vampire beeing in his human form. After loading this save game again my vampire will have the auto applied dark form face details the next time he switches into his dark form.
But when saving a game with my vampire beeing in his dark form, he keeps the appearance which I chose for his dark form in CAS, so the bug doesn't happen in that case.
(So actually I am forced to always switch my vampire into his dark form before saving a game, if I don't want to have to re-edit him everytime I'm loading my save game.)
I also tested this with all mods removed but the bug still remains.
@crincrit
Please feel free to download this vampire from my gallery to see that the gallery preview picture (no dark form face details) doesn't match the sim actually loaded in CAS (suddenly having auto applied dark form face details).
Origin ID: Avianator