[shmerl]

Github supports SVG but doesn't support AVIF still.

[SchemaLoad]

iOS only recently added support for AVIF, and there are still some in use devices which can't update to a version which supports it.

[shmerl]

I don't think it's a big reason not to allow it, since they allow webm with AV1 video which shouldn't be any better than AVIF in practice for compatibility purposes.