You don't need to do anything at all to divide tracks using MakeMKV + DVD Audio Extractor.

It takes more like 5 minutes for me to then rip the decrypted hi-rez files for an entire LP to hi-rez stereo FLAC with DVD Audio Extractor. But once the blu-ray has been decypted, it shouldn't be taking an additional hour for DVD Audio extractor to do its work. MakeMKV takes a while to decrypt a blu-ray (maybe a half hour to an hour IIRC depending on resolution and amount of content on the disc). I just keep the page bookmarked and copy & paste when asked for the key. The key is like 40 letters and numbers, so I'm not sure if it actually changes or you just have to simply re-enter the same key again. It's a sticky in the news and announcements of the discussion board on the MakeMKV site.

AFAIK it's continuously in beta but you need to re-enter the key periodically to update to the current beta version. Click to expand.You're making this far more complicated than it is and/or you're doing it incorrectly.

Makemkv evaluation expired