The thing that makes X (Twitter) tricky for downloaders is not a special protection layer; it is URL gymnastics. Tweet video lives at video.twimg.com behind an HLS manifest, but the URL on the page is a blob: reference that exists only in browser memory. The actual manifest is fetched by JavaScript at playback time, and its location is not visible in the rendered HTML. Anything that tries to scrape the tweet HTML and find a .mp4 URL will come up empty.
VidMost’s smart sniffer has an X-specific adapter that watches network traffic instead of parsing HTML. The .m3u8 manifest is detected when the player requests it, available variants are listed in the right sidebar, and the built-in browser handles sign-in for content visible to that account. If a platform change outpaces the adapter but the video still plays normally, browser recording mode can provide an alternative capture path. No mode can recover a deleted post because deletion removes the source entirely; that is a platform constraint, not a tool capability.