will there be a JavaScript Runtime for yt-dlp in QMPlay2?
https://github.com/yt-dlp/yt-dlp/wiki/EJS
Isn't Deno enabled by default?
Deno isn't available for all (older) systems, and building it from source is not for the faint of heart. I've played with using it via wine but while that does work it is slow and probably error prone.
From the looks of it there is no easy way to enable additional runtimes, but you can just add multiple ones on the command line (e.g. --js-runtimes node --js-runtimes quickjs to let yt-dlp pick the one from deno/node/quickjs that's available.
Quickjs is slow too, but also comparatively tiny and can probably be built on any machine that can also run QMPlay2.
(On the plus side, parsing has become a lot (about 2x) faster when there is no java runtime (or with --no-js-runtimes; because yt-dlp doesn't do any solving itself anymore), which would almost be an argument to provide a "quick play" option or something like that ;)
NB: https://github.com/yt-dlp/yt-dlp?tab=readme-ov-file#configuration