This isn't a Twitter echo site but it is a page that contains some embedded Twitter videos.
https://www.nhl.com/fr/canadiens/newsI've scrolled the page down to an article with this subordinate URL:
https://www.nhl.com/fr/canadiens/news/pezzetta---cetait-agreable-de-voir-ces-enfants-sourire-/c-335429390That page contains a collection of articles. You have to scroll to the individual article, scroll it down about a further screenload & a half, then click the button that says "En voir plus." That's French for "See more." Clicking the button expands the article I am going to be talking about here.
A short way into the article, there is an embedded Twitter video. I had to reload the page a couple of times to get VDH to recognize this. As you can see, I have not hit Play on the Twitter video.
I downloaded the 8:38 variant you can see in that image. It took only a few seconds. It appears the Habs web site provides excellent download service, unlike certain other sites we won't mention. The download did appear to hang at 99% complete for rather a bit. But then it generated the MP2T error. So I enabled the VDH setting. As you reported, this didn't work either. I ended up with a zombie download on the VDH blue dot status menu. Clicking the entry on the status menu should tell VDH to kill the download. But it didn't do that in this case. I had to reload the extension to clear the zombie.
So of course, I went to the ffmpeg solution. That worked fine. Here's the results:

You can't tell from that image but from other information I collected, I can tell you the download completed in 17 seconds. It played fine in VLC, video & audio, right to the end.

So I suspect ffmpeg still works on Twitter. The URL for the m3u8 HLS manifest for this video is on
video.twimg.com, not the Habs web site, so I would expect the ffmpeg approach still works on Twitter.
But I would still like a member of Twitter to post here telling us whether the HLS as M2TS setting in VDH works on Twitter itself. Maybe it does, maybe it doesn't. I'd like to get explicit confirmation either way.