How can I re-init config in javascript API?

HI there,
I know bellow code works fine.

      WALK.COVER_JSON_URL = "./cover.json";
       WALK.ASSETS_URL = './assets_a/';
        var config = new WALK.SceneLoadConfig();
        WALK.init(config);

but as long as I have a requirement that I need to shift to a different assets_url './assets_a/ when a button is clicked, so how can I implement this?
I directly call bellow code from a click event:

  WALK.ASSETS_URL = './assets_b/';
        var config = new WALK.SceneLoadConfig();
        WALK.init(config);

yet I see glicthy shadows when going from scene to scene. so l’d like to know if there are any available API(s) in WALK like WALK.reinit(config); so it can shift from one ASSETS_URL to another using javascript lib?

What kind of asset would you like to load from a different URL when a button is clicked? Perhaps there is some other solution that changing the ASSETS_URL path