You can edit answers both while the report is running and when it is over and your answers have been already sent.
In order to do this use the standard Slack function message actions:
1. Hover over the message you'd like to edit.
2. Click the "Show message actions" button on the menu that appears when you hover over the message.
3. Select "Edit message"
4. Edit the message.
If you've already submitted your answers and has changed one of few of them after that, the results will be changed everywhere including History, but not in a message with the results sent by email.