Web App built-on CORS header Access-Control-Max-Age
Using the built-in CORS support in App Service for an API Web App, we can't specify header 'Access-Control-Max-Age' or any other headers besides 'Access-Control-Allow-Credentials' and 'Access-Control-Allow-Origin'.
We would like to use the App Service built-in CORS because it's easy to manage all the different allowed origins from there, but we need to be able to set headers like 'Access-Control-Max-Age', 'Cache-Control', and 'Vary' to optimize the OPTIONS calls.
Thank you for the feedback! We will keep this item open, but at this time we do not have plans for this feature.