Ability to block further comments on ideas

Whilst I see some value in allowing users to comment on some ideas that have been shipped, I would like to control what ideas can and can't receive comments as 95% of the time, the comments are iterations on what has been shipped and NOT related to the existing idea, which is really frustrating as we then need to create the (new) idea manually.

Ideally if the comments on an idea are CLOSED the (public) user would have the option to create a new idea, and internally we'd see that it was generated (linked) to the previously shipped idea.