Hey @Michael Nortei 👋🏼 Shauna here from Support!
Unfortunately there’s no way to prevent users from going back and ‘rating an old conversation’ if there hasn’t been a rating sent. That setting for “prevent Customers from changing their rating” - only works on conversation ratings previous submitted and not left blank. I'll definitely let the team know that this is something you would like to see in the future though. Happy to submit that as a feature request for you 😊
I know it may seem self explanatory, but as it's great for the Product team to be able to see why introducing particular features is so important, I'd love to know a little more on your use case here 🚀