"Run" button at download diaog required: OpenDownload² Replacement/Alternative?

Hi…is there any replacement/alternative to the add-on OpenDownload² that adds a “run” button at the download dialog? I download stuff all the time and find that my download folder fills up very quickly because every file has to be saved, and then deleted if unwanted. Many other browser have this “run” functionality built in.

See:
https://addons.mozilla.org/en-US/firefox/addon/opendownload-10902/

Files that are opened with the “run” button are saved to temp directory that are then deleted after a while.

This ability to “run” files without saving them is sorely missed in Firefox 57. Is there any plans for an add-on with this functionality??