Mitt will have about as much pull at the 2016 convention as Rick Santorum had in 2012.
If he is polite, he might get a non prime time speaking spot. Everyone knows what Trump said about Romney recently is true. He could have closed the sale in the second and third debates. He chose not to do so.
Obviously he’s not. He pops up fairly regularly to torpedo conservatives. Not sure how that qualifies as ‘done’