Hair Proxy is a Blender addon from halitree that combines the features of hair curve and mesh objects. It creates a mesh proxy so that mesh object capabilities, including shape keys, physics, rigging and mesh modifiers, can be used on hair curves, with geometry nodes updating the shape.
With it, you can add shape keys and hair dynamics to hair curves in just a few clicks. Shape keys let you create alternate hair styles, tweaks, or loop animations. For dynamics, you can sculpt a rough shape, enable hair dynamics and let Blender handle the simulation, for example to make a character's hair fall naturally behind the shoulders.
If you want to keep adjusting after simulating, the Apply to Sculpt option lets you make sculpted changes to the result. The addon requires Blender 3.3 or higher and ships with documentation, and halitree maintains a BlenderArtists thread for updates and support.