[Plugin: Advanced Custom Fields – Taxonomy Field add-on] Add text input to the taxonomy field

Currently the taxonomy only accept dropdown option. What I need is able to add new item in the taxonomy, so it would be great if using the original text input method. Is this feature will be added on next release? Or can anyone tell me how to make change the dropdown option into text input?

http://wordpress.org/extend/plugins/advanced-custom-fields-taxonomy-field-add-on/