I'm working on a PWA with Web assembly that requires our server to be in a Cross Origin Isolated state. This is relatively new in the Web world. It means our server must supply the COOP and COEP headers in our responses to the client. The COEP header must have the value of require-corp. This unlocks API's like SharedArrayBuffers, which is a requirement for my application. Since Arcgis's CDN does not provide the CORP header, external cross origin assets can not be loaded. I have been able to host the API on our server, but the Base Map Gallery tries to download thumbnails from an external CDN which fail.
Here is a document explaining what COOP and COEP mean and why developers need this support.
https://docs.google.com/document/d/1zDlfvfTJ_9e8Jdc8ehuV4zMEu9ySMCiTGMS9y0GU92k/edit#
It would be nice if the Arcgis CDN supported this header for developers who work in a Cross Origin Isolated page.
