Hi :)
new version of EasyAppointments 3.11.16 is here. We have fixed issue with deletion of advance redirect settings. Also we implemented new feature. Now you are able to use form fields in redirect urls. Example:

https://example.com/customer_email={{email}}&customer_name={{name}}

in this example we have name and email custom field passed to that url. :)

Best regards,
Nikola