Example avatar: avtr_fc286e2a-fd89-42ac-8c0b-53e6d8e39bd9 (private)
The impostor version of this avatar has a lot of artifacts where portions of the hair detach from the head. This is likely because this avatar uses a constraint to make portions of its hair visible in first-person view.
You can recreate this using Modular Avatar's Visible Head Accessory component, or manually construct it by creating a clone of the Head bone, connecting it to the Head bone with a parent constraint, then moving some mesh components from a child of the Head bone to the new cloned-head bone.