When editing the Ask for Feedback (Request Feedback) Notification template, you are not able to select the option for Specify Different Template for Each Form.
Reproducing the Issue
Go to Admin Center>Email Notification Template Settings>Select "Request Feedback Notification"> Here you cannot select "Specify Different Template for Each Form"
The Ask for Feedback Notification cannot be changed per template. The template settings here are what will act as a base for the notification.
When you select Ask For Feedback from the Team Overview, you will have the opportunity to edit the notification content before you send it out.
Ask for Feedback, Notification, Specify Different Templates, PM, Performance Management , KBA , LOD-SF-PM-EML , Emails and Notifications , How To