www.makemkv.com

I just received my copy of the Schindler's List 25th Anniversary 4k release, and was stunned to see that the main feature track was a whopping 90GB (reported in the MakeMKV selection UI, not the final ripped mkv size). As a mostly black and white movie released 25 years ago, I was expecting something much smaller, despite the three hour runtime and Dolby Atmos/Vision enhancements.

What's the largest single track you've seen when backing up 4K releases so far?

King Kong UHD @ 74.8GB. It's 3:20.08 long though so the bitrate is still probably being constrained.
Forrest Gump UHD is close second. 70.8GB and 2:22.08 long

My largest are Blade Runner 2049 and Superman The Movie. Both are 83GB+