It should be possible to open the TemplateWizard when the insertion point is in an existing template's wikitext, and be able to edit all parameters. Requested [here](https://en.wikipedia.org/wiki/User_talk:Samwilson#Template_parameters_wizard), [here](https://meta.wikimedia.org/wiki/Talk:Community_Tech/Template_wizard#Possibility_edit_for_template_already_inserted) and [here](https://meta.wikimedia.org/wiki/Talk:Community_Tech/Template_wizard#Malformed_parameters_and_editing_already-inserted_templates).
Both the [[ https://en.wikipedia.org/wiki/User:%D7%A7%D7%99%D7%A4%D7%95%D7%93%D7%A0%D7%97%D7%A9/TemplateParamWizard.js | TemplateParamWizard gadget ]] and [[https://de.wikipedia.org/wiki/Wikipedia:Technik/Skin/Gadgets/Vorlagenmeister | Vorlagenmeister ]] are able to do this with plain wikitext in the editor. However as soon as CodeMirror or wikEd is turned on, neither of them work as expected. They either fail to recognize the already inserted template or just don't work.
Questions for investigation:
1. What's involved in parsing the template from a textarea? Can we offload this to Parsoid or reuse code from Vorlagenmeister/TemplateParamWizard?
2. What are the potential pitfalls of doing this, if any?
3. What's involved in making template parsing work with CodeMirror enabled?
** Note that CodeMirror adds another "surface" to the editor. So //maybe// if we point to the right surface, we can parse the wikitext like normal.
4. What's involved in making template parsing work with WikEd enabled?