www.makemkv.com

I see 2 81GB dolby vision dolby atmos 7.1 films on this disc in MakeMKV. One says "Apocalypse Now - Final Cut - UHD-FPL_MainFeature_t04" and the other says "Apocalypse Now - Final Cut - UHD-FPL_MainFeature_B_t05". As far as I can tell there isn't a difference: they both have the same subtitle options, audio and video quality. Any ideas why there'd be 2 of what looks like the exact same film on the disc? Like I said, both have the exact same language, audio and video quality as well as subs.

I don't have that disc, so I can't say for certain. Do both titles have the same segment map?

Blu-ray.com says there is 3 versions of the movie spread across two discs.
(https://www.blu-ray.com/movies/Apocalyp ... 62/#Review)

MakeMKV usually shows the main feature twice. One with the mpls file as source, the second with the corresponding m2ts file.
Main difference difference is that the mpls file holds chapter-info where the m2ts file doesn't.

Ah that explains also why I have 2 for Dune as well. I noticed that one was mpls and one m2ts as you said. For fun I ripped both and compared them with MediaInfo and they were identical in terms of the video/audio. Much appreciated!

OP wasn't asking about the chapter stripped version, which ALSO shows up. He was asking about the two versions that show up with chapters, the second is earmarked as "-B".

Obviously this is too late for OP, but I stumbled upon this myself today (with the BluRay, not UHD). They indeed have different segment maps, however the main feature is one large segment and identical for both. They only differ in short segments that show logos.

Probably has something to do with adding end credits, since Coppola prefers the no-credits version but legally they have to attach them.

So, one playlist with, one playlist without.

Typically in situations where there are two apparently identical files to rip, I've noticed that if a running commentary is provided with the movie, it's usually imbedded in the second one. Usually if you play the movie directly from the disc, the visual menu will give you a choice to either turn on or off the directors commentary (or whoever is talking).

If you're not sure which is which and commentary is offered, rip them both and see what happens.