This is an experimental method made by me to convert an animation of particles made with shapekeys into an armature animation by automatically assigning a bone to each mesh island

it uses a combination of constraints, geometry nodes, plus a few steps demonstrated in this YouTube video

Note that this method only works for particles that are made of mesh not instances, and their vertex count has to be constant throughout the animation

The goal of it is to allow you to reduce the file size of the animation or export it as rigged animation for formats like fbx or glb