I was a bit unsure about using this latest iterration as the downloads no longer show up in ther main Firefox download page -but it does seem pretty reliable once the Download Helper coap is installed. The 9.0.2.12 version seems in practice an improvement - though individual download records now have to be removed from the app pop-up indiviually rather than the Firefox dowload page in en masse.
I notice this version will download Twitter (X) video files, though you have to be careful to select the right fule to download.