It looks like imgix is rolling out avif support to users that request beta access (see https://twitter.com/letsgoheadless/status/1441446519102607366) I tried to set fm to avif manually in the image urls I get from the dato content delivery api (Output Format | Format Parameters | imgix URL API Documentation ) but I guess datocms will have to have beta access for it to serve avif files instead of png as it did when I tested.
Just being able to manually set fm to avif would be great as a mvp avif “solution”.