Is it possible to add another option type to Core Form Options?

In the AEM Core Form Option component, the authoring dialog has a dropdown for option 'type'.  Out of the box, the available options are 'Checkboxes, Radio buttons, Drop-down, and Multi-select dropdown'.  Is it possible to add a custom option to this list (like a group of buttons)?

It is easy enough to change the authoring dialog to offer the option, but the Sling model implements the following Options interface that defines an enum for possible values:  

Is it possible to add a custom enum value (like BUTTON_GROUP) without changing the source code? I tried extending the OptionsImpl class, which is the sling model that uses this interface, but I can't override its getType() method that returns the interface's enum Type to return my own enum with the new value