Textured low-pol undead organist character
I improved lighting on the hair by using this shading trick:
https://simonschreibt.de/gat/airborn-trees/
While that link discusses foliage, the same lighting problems (and thus same solution) applies to hair as well. It describes copying the normals from a base surface onto the foliage planes, rather than using standard normals on the planes.
In Blender, this is done using the Data Transfer modifier:
https://blender.stackexchange.com/questions/98156/copying-vertex-normals