Exclusive to the IOS version of the Brave Web-browser is a "Playlist" feature that allows to enqueue and playback media on sites like YouTube. https://brave.com/en-in/playlist/
Seeing as all web browsers on IOS are based on Webkit, it would be nice to have an equivalent feature on Firefox IOS, perhaps in the form of an Add-On.
Update: the Reading List feature may be a good backdoor for a “Playlist” feature ala-Brave.