Im wanting to do something similar to the user in this thread but running into the same issues as them.
The old particle system allowed you to create collection or models that would replace/follow the particle hair curves you created in a mesh (Ontop of allowing a random object from said collection to be selected for each hair particle) .This was handy especially on Bird models where you likely wanting to to use a collection of variations of feather images as ‘Hair’ cards for the plumage of the model.
Is it possible to do the same with the new Geo Nodes system, creating a set of Hair particles (That are just 2 points, a Root and Tip) brushing and styling them in the sculpt hair mode, and then having a collection of meshes to function as hair/feather cards be distributed across the mesh following the vector and direction of those hair curves/particles. Im hoping as it has been three years since the linked thread there is a bit more answers about methods to do this.