Downloading blob: URLs fails

If I attempt to download a blob: URL from a site, I am presented with a dialog asking to choose an application as destination, and then after choosing I am presented with "NetworkError 301: Protocol 'blob' is unknown". (Replicate by, for example, going to https://www.photoeditorsdk.com/, choosing "Try HTML5 editor", and then hitting Export in the editor.) I think that the browser probably hands off the URL in question to the download manager, which does not understand blob URLs (and should not). The browser should handle this itself; it is the only thing that can understand blob URLs, which may be (and in this case was) dynamically generated and stored in memory only. (If handing off to the download manager is still required, then perhaps the browser should serialise to a file or a data URL and then hand that URL to the DLM.)