This is neccessary to texturize the fur/hair according to the UVs of the base mesh it is bound to (not sure what the process here is, sampling on binding or writing on export).

Does anyone have some idea how to get hair over to Unreal with RootUVs or how to implant this info with a script solution afterwards into the alembic cache somehow?
This thread and maya script sounds like it tries to solve this, too:
https://devtalk.blender.org/t/adding-uv-data-to-alembic-on-export/24463

Cinema Version is 2024, maybe this is solved in newer verions?

Thanks for ideas!