I've been finding that a large number of hair
retextures are an internal mess. Some reuse the original package, and add their uncompressed textures, without bothing to remove originals, which double bloats the package, and puts a memory strain on the game. I've even found solid black speculars as 1024 x 1024 uncompressed, which is just silly.
To fix this one issue, you need to know how to use
S3PE and an imaging program.
Texture Tweaker may wwork, bbut I have never used it. I open the package in s3pe. Very often, a hair package that is more than 6,000 kb will have issues. Select an image.
S3PE often shows text in the preview window of uncompressed images. I will export all images to a work folder. An uncompressed 1024 x 1024 image will be over 5,600 kb, whereas dxt5 is around 1,300 kb. Import the texture to GIMP or whatever, then export as dxt5 with mipmaps. Use a new name and hold the original incase the hair actually does look bad in game... but highly unlikely. Replace the uncompressed images with your compressed images and save. Test in game.
Bloated hair is my greatest foe, since I am a hair ho!!! Is more than 5 GB too much???
Shiny, happy people make me puke!