Ah thats too bad, the flat wavy hair style looks great but not being able to rotate the strand is problematic.
I found a workaround though (which introduces all sorts of problems I’m not aware of I am sure, probably with deflect emitter).
If you add a plane to the emitter(or just disconnect one of the quads on the scalp) you can place the hair strand on that plane and then exactly control the strand roll by rotating the plane around its normal.
