You could try optimizing your code…
For example you are calling getMousePos 4 times in your mouseMove function.
Call it once and assign the value to a vector3D that’s declared once, outside the function.
i.e let currentMousePos = new THREE.Vector3();
And at the start of the move call currentMousePos = getMousePos(e);
You could go deeper, but that’s a start.
That should give you a performance boost 