Possible, alternative "container" for our releases

[Valeyard]

That's basically what MKVs support, at least in theory. You can do what you want by creating a program to make the menu to mux into MKV. Or you can use the already available 🔍MP4menu program there's even a 🔍GUI for it. There's no guarantee of player compatibility with the menus though, and you lose the MKV features. You can also do it with 🔍PGMX which is a modification of the MKV standard, but requires payware to make the menus - and playback is only supported if people use the propriety player (although the files can be played as normal .mkv files if you rename the extension).