Best Practices for Handling mat4 Attributes in WebGPURenderer and Resolving Geometry Update Errors

I previously used WebGLRenderer to create a mat4 attribute and pass it to the shader, but after switching to WebGPURenderer I encountered issues: WebGPU does not directly support mat4 attributes and has a limit of 8 vertex buffers. Although simulating a mat4 with four vec4 attributes is possible, it feels wasteful, and updating the mat4 in WebGPURenderer has become problematic.

1. What is the best practice for passing a mat4 attribute using WebGPURenderer? Should I emulate it with four vec4 attributes or is there another approach?

2. I attempted to mimic the handling of an instanceMatrix in instanceNode as follows:

JAVASCRIPTCopied
const buffer = new InstancedInterleavedBuffer( instanceAttribute.array, 16, 1 );

this.buffer = buffer;

const bufferFn = instancedBufferAttribute;

const buffers = [
    // F.Signature -> bufferAttribute( array, type, stride, offset )
    bufferFn( buffer, 'vec4', 16, 0 ),
    bufferFn( buffer, 'vec4', 16, 4 ),
    bufferFn( buffer, 'vec4', 16, 8 ),
    bufferFn( buffer, 'vec4', 16, 12 )
];

matrix = mat4( ...buffers ).toVar();
currentMatrix.assign(matrix);

However, when my geometry changes (disposing of the old geometry and creating a new one), this code results in an error. Why does this happen and how can it be fixed?