Thanks for pointing them out, I have added the ambient & diffuse fix to my list. I could see that the Twi'lek male (twilek_m.mdl) & Corran Falt (n_correnfalth.mdl) had the issue, but the Sith Officer head (sith_off.mdl) looked correct already.
Also, the twilek_m02.mdl, twilek_m03.mdl, n_komadh.mdl, n_xorh.mdl, & n_zharh.mdl models in TSL have the correct settings, but are not used in-game. By default the TSL heads.2da file uses twilek_m for all male Twi'leks, and just swaps the alttexture column. So in the meantime, editing the heads.2da file can solve the issues as well. I will still eventually fix the model though, because I can't just let things go 😝