Dynamically changing a point's texture in a point cloud

Questions
1

I created a simple point cloud with a few hundred points. I have a texture that’s set up as a spritesheet and I’d like to have each point correspond to a sprite sheet offset. For colors i know that setting vertexColors: THREE.VertexColors will allow me to individually update the points of the cloud but how do i do that with textures?

this.sprite = loadedTexture;
this.sprite.wrapS = THREE.RepeatWrapping;
this.sprite.wrapT = THREE.RepeatWrapping;
this.sprite.repeat.set( 0.1, 0.1);
this.sprite.offset.x = 0.9;
this.sprite.offset.y = 0.9;

let materials = new THREE.PointsMaterial({
        size: 4,
        vertexColors: THREE.VertexColors,
        map: this.sprite
});

let geometry = new THREE.Geometry();
for (let i = 0; i < this.totalPoints; i++) {
    geometry.vertices.push(new THREE.Vector3());
    geometry.colors.push(new THREE.Color());
}

this.pointCloud = new THREE.Points(geometry, materials);
this.scene.add(this.pointCloud);
2

I’m not sure if this works out of the box. Looking at the docs none of the point drawing stuff mentions this feature. You will most likely need to create your own shader with the offsetting logic, along with a custom buffer geometry to hold an index or the actual offset.