Dear John McWilliams1,
Good day! Thank you for posting to the Microsoft Community.
This forum primarily focuses on Microsoft 365 and Office built-in features.
Unfortunately, the built-in reminder feature in Microsoft Forms will send reminders to all recipients. However, it should be possible to use Power Automate to send reminders only to those who have not yet responded. Therefore, I sincerely recommend posting your concern to the specific channel. Microsoft Power Platform Community by clicking on Post a question, as our forum has limited knowledge in this area.
Members and engineers over there are proficient in the knowledge of Power Automate issues. We are sure that our experts from that team can address your query effectively and accurately.
Thanks for your understanding and cooperation! Hope you have a nice day!
Sincerely,
Ralph | Microsoft Community Moderator