luceos I have tested the new extender on FF test forum now. Works perfectly, thank you so much for thinking about our case!
One question though, is there any way how can I add a custom upload option (such as Anonfiles, or pretty much any free upload option)? Imgur, Quiniu and AWS S3 are the only upload options that I see. Are those hard coded into the extension? If not, could you please share an example extender for other services? Anonfiles API is pretty basic, and since AWS is paid and Quiniu is Chinese, ability to use basically any free service would be perfect.