When using the xcancel.com frontend for Twitter, any attempt to open a direct image URL will result in an error ("Failed to verify signature", or sometimes just 404.

Their frontend does not proxy images and loads them directly from twimg. Not ideal, but it's one of the very few ones working reliably at the moment.

The extension does not recognize cdn.xcancel.com, and does not offer an option to redirect back to original. Ideally, it would be good to have an option to exclude twimg.com from the extension entirely to avoid cases like this.