I downloaded the VOD with TwitchDownloaderGUI since it freezes up on Twitch at 2:48.48 VOD timing and 2:41.06 in speedrun timing. Already had audio/video desync by that time.

From viewing the downloaded VOD (5.88 GB), here's what happens:

1. At 49:06 VOD timing and 47:24 speedrun timing, there's an audio glitch and video is frozen for 5 seconds. You see the speedrun timer jump from 47:25 to about 47:30. Video then lags behind audio for about 5 seconds from this point onward. Very jarring to me at least.
2. If you skip to 2:40:00 VOD timing and 2:37 speedrun timing, we're at the end of the 2nd battle of the semifinals. You see KEI's winning attack. Seems strange to block at all and waste time, but regardless, the music shuts off while sounds effects remain.
3. The 2nd trip to the semifinals begins at 2:42:42 VOD timing and 2:41:00 speedrun timing. Sound is completely muted by 2:42:51 VOD timing and 2:41.09 speedrun timing where the VOD freezes again. Speedrun timer jumps to about 2:41:14 for another 5 missing seconds.
4. Semifinals against KEI, COMET, NISHI and the finals against SHIN are played completely muted.

I didn't watch the whole 4 hours so there could be other video freezes. Just given the last 4 and arguably hardest battles are all muted, I think that's enough reason to reject the run. Had to be self-verified given it was the first submitted speedrun.

It's a 7 Year Old Video Archive of a Stream that happened LIVE with Newer Twitch Encoding messing how it's playing back Audio & Visuals NOW VS. It how it was working and playing perfectly fine for nearly 8 Years with it also being "Grandfathered In" as The Example of Run waiting for it to be surpassed & replaced by a Faster Run and only recently started having playback issues.

Majority of the Issues you're mentioning have only occurred fairly recently due to how Twitch has been handling Older Archived VOD Content as of late and not reflective of how The Run originally went or what folks were watching / witnessing the Stream happen 7 Years ago.