Rather than do an MKV you can use the MakeMKV software to do a full backup of BD/UHD. This maintains all info and takes handling of forced subtitles out of the equation, assuming you have a player that can handle full BDMV rips. After you have done your first 50TB and backed it up as a mirror no need to stress anymore about spaceVery interesting thread, I'd love to digitise all my blu-ray collection of both 2K and 4K content.
Is it possible to make 1:1 copies (same as original)?
I suppose non-lossy compression could be allowed to keep file sizes sensible.
I presume the MKV container supports and maintains HDR information?
Remarkable to think that only 20 years ago my entire PC had 5Gb capacity, now I just rip away regardless