Editing the Edit mode of the Responses page won't be possible as this page is auto-generated at the installation of the module and cannot be extended or changed in any way. This means that if you need to implement such a functionality, you will have to reimplement the whole logic by yourself, pull up the old responses from the base and populate them to the new form.
All the best,
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items