There are at least a dozen possible uses for the word template in tiddlywiki. There is content, transcludable and view or edit templates to name a few. All can be delivered to all tiddlers and many are made conditional.
We could have a tiddler template which you clone to a new tiddler or one just with text field content used in new tiddler buttons.
A new tiddler could just have a field set to the template name such as todo then the details are applied through the view template.
Since the cascade mechanisium was introduced you can even conditionaly use different view and edit templates altogether and more.