About mkvmerge:
I have no issues with it either.
In fact, it’s even better because it directly shows QuickTime-related problems,
whereas FFmpeg acts like everything is fine—even when audio/video is broken.
If you followed the information on MKVToolNix you would know that there are no QuickTime-related problems. For whatever reason, the author (Bunkus) has decided that if the program finds video files that are damaged in some way, the resulting output remuxed file will be labeled as V_QUICKTIME. See
https://gitlab.com/mbunkus/mkvtoolnix/-/issues/2555 as an example. It's one man's decision to go against the standard method. This has been going on for years, and every few months it becomes a hot issue on this forum when someone gets a botched download. Usually when some Bro here decides to show his ignorance.
Getting back to the OP and the problem with MSVCP140_1.dll and MSVCP140_2.dll, they MIGHT have reappeared if Windows had been restarted after the install. Also, I've noticed for a while that we see a lot more problems posted on the forum when the latest SF update falls in line with Patch Tuesday.
And finally, as has been my normal pattern since Windows 386, a year after Windows 12 comes out, I will purchase it, and it will be my primary Windows version. Until that time, I will continue to use Windows 10. I choose what I use, not Microsoft.