Using a ListBoxFor with Select2

Question

I've setup Select2 in a form to create a list of strings. It also allows me to search and create my own items.

@Html.ListBoxFor(model => model.Schemas, new SelectList(Model.Schemas, "", ""), new { id = "schema-select" })

My Jquery to initialise the control is:

$('#schema-select').select2({
theme: "bootstrap-5",
width: $(this).data('width') ? $(this).data('width') : $(this).hasClass('w-100') ? '100%' : 'style',
placeholder: $(this).data('placeholder'),
closeOnSelect: false,
tags: true,
ajax: {
    dataType: 'json',
    url: '/Select2/FetchSchemas',
    delay: 250, // wait 250 milliseconds before triggering the request
    minimumInputLength: 2,
    data: function (params) {
        var query = {
            schema: params.term
        }

        // Query parameters will be ?search=[term]
        return query;
    },
    processResults: function (data) {
        // Transforms the top-level key of the response object from 'items' to 'results'
        return {
            results: $.map(data, function (item) {
                return {
                    id: item.text,
                    text: item.text,
                }
            })
        };
    }
}

});

I also have this method:

 [HttpGet]
    public JsonResult FetchSchemas(string schema)

{
    List<viewSchemaList> list = new List<viewSchemaList>();

    if (!string.IsNullOrEmpty(schema))
    {
        list = db.viewSchemaList.Where(x => x.text.StartsWith(schema)).ToList();
    }
    else
    {
        list = db.viewSchemaList.ToList();
    }
    return Json(list, JsonRequestBehavior.AllowGet);
}

Everything works fine for creating a record but I'm struggling to get it to work for editing the list. Is this even possible using a ListBoxFor or do I need to change it to use the html SELECT tag?