As they are the proposed successor of XUL, I wonder if I can still - somehow - continue my OpenDownload² extension.
@billm might know.
There’s no way to do this right now. I posted this to https://webextensions.uservoice.com/forums/315663-webextension-api-ideas/suggestions/9468588-allow-extensions-to-add-to-the-download-dialog
Thanks, I’ll watch that.