how to identify or listen a second mouse wheel with DOM events.
document.addEventListener( 'wheel', ( e ) => {
const delta = e.deltaY > 0 ? 0.1 : -0.1;
const old = $Camera.data._zoom;
let zoom = old + delta;
zoom = Math.min( Math.max( zoom, 0.1 ), 4 );
if('weel2') 'stuff...'; // what the hack for this ?
} );