Add new tags to Chosen Widget or Display All on Autocomplete Deluxe
For Autocomplete Deluxe, there looks like there's a bug in the code.

Update line 287 of the js file autocomplete_deluxe.js to include a question mark, as shown in the third last line of this block of code:

Drupal.autocomplete_deluxe.SingleWidget.prototype.setup = function() {
  var jqObject = this.jqObject;
  var parent = jqObject.parent();

  parent.mousedown(function() {
    if (parent.hasClass('autocomplete-deluxe-single-open')) {
      jqObject.autocomplete('close');
    } else {
      jqObject.autocomplete('search','?');
    }
  });
};


Also update the maximum results shown in line 30 of the module by changing to $limit = 0 (the default of 10 overrides whatever you have set for the field):

function autocomplete_deluxe_taxonomy_callback($field_name, $tags_typed = '', $limit = 0) {