Can`t extend qli-group-edit-view

I`m trying to extend the qli-group-edit-view from SDK by using the following custom code:

import customization from 'APP/js/core/customization';
import FilteredListView from 'VIEWS/quotes/qli-group-edit-view';

console.log(FilteredListView);

class customQliGroupEditView extends FilteredListView {

    initialize(options) {
        console.log('ínitialize');
        alert('initialize');
        super.initialize(options);
    }    
};

customization.register(customQliGroupEditView);
 
export default customQliGroupEditView;

console.log(customQliGroupEditView);
console.log(customization);

So far I`ve been only able to log the FilteredListView and stuff, but I can`t extend the initialize method at all. It just ignores anything. I have successfully extended the VIEWS/edit/modules/quotes-edit-container-view by using thie same approach. Is there anything I might be missing regarding this file specifically?

Update: I`m using SDK 49.0.686-1.4.2-2 and not even the quotes-edit-container-view is extendable anymore either. It's not working any longer.

Thank you,

Silvio