Looking around, Firefox already supports most PWA features/APIs. It's primarily just missing support for web app manifests and the ability to install web apps (ATHS or whatever you want to call it). There's some newer background synchronisation APIs ...
For anyone jumping to the end of the thread and wanting to know how to configure this correctly, see these 2 instructions:https://connect.mozilla.org/t5/ideas/choose-how-firefox-handles-the-files-you-download-from-the-web/idc-p/7476/highlight/true#M3...
Personally, this just seems to duplicate a section of about:addons, something I look at about 3 times a year. Not sure why something so infrequently used needs to take space in the toolbar.The only new use seems to be when permissions need to granted...
