Dear Bobby,
Thanks for your updates and confirmation.
Based on my multiple tests, you can filter the specific response by using Uri formapi/api/forms('id')/responses?$filter=id eq responseid from Microsoft Forms. However, it is a just filter not the actual response. Currently I'm afraid that there is no Uri getting the specific response and we can only delete all responses from Microsoft Forms by the DELETE method.
As a possible workaround, you can use the SharePoint Online list to store and dramatically remove the responses automatically by a flow and remove all the responses in Microsoft Forms after each run of the flow.
For example, you can create a calculated column ExpireTime in the list to calculate the expiration time automatically by just using the formula =SubmitTime+90.
You can create the flow as follows.
Filter array: utcNow()
Compose: items('Apply_to_each_2')?['id']
Result:
As our product developers are willing to hear the users' suggestions, I kindly suggest you submit your feedback on the Feedback platformto our product developers so that they can know your requirements and ideas for product improvements. I hope that there will be a corresponding API call letting users remove the specific response in the future.
Thanks for your understanding and have a nice day!
Sincerely,
Cliff | Microsoft Community Moderator