Hat accessory floats above head?

Hi. This accessory should be assigned to the head bone only and vertex painted with black color, no need in uv_1. For more info,please provide your blend

The name of the vertex group must correspond with the bone's name, not an object's one.
- clone any earrings, export the blend, open, delete only s4studio_mesh_1;
- File - Append - the blend you shared - object - Extracted Mesh, append;
- delete rig.001 and bone_bone_shape.001;
- select this mesh and switch to Edit mode;
- delete an existing vertex group with - button, create a new one with +, double-click on its name and paste b__Head__
- in 3d view select everything with A and click on Assign;
- rename UV map to uv_0;
- expand color attributes and create a new one, name it color0, choose Face corner and Byte Color, leave the color as black, this disables morphing;
- id advice to move uvs in uv_0 elsewhere, so that all this hat space isnt wasted, but its up to you;
- give the mesh cut 0, import back into the earring package, do not re-use the original, recategorize if needed;

uv_0 is responsible for how textures are projected on the surface of the item.
uv_1 is responsible for morphing, you create it when you need your item to morph. Morphing is when an item goes from one shape to another, which is what happens during face or body customization. Since ts4 does not use sliders for anything other than body mass/muscle, a more accurate way of calling these modifications would be "morphs", hence why.
uv_2 is something only heads have

Generally, you want everything to morph unless it makes no sense for it to do so. For example, it makes no sense for this sprout to become wider when you change the width of the head, so it shouldnt, but all regular accessories would need to follow the head's and body's changes to not clip into them.