The last time I looked at it (a couple of years ago), 4K required specific BD drives with older firmware. I had a “compatible” drive listed by AnyDVD HD, but it had a newer firmware and wasn’t downgradeable. Never bothered looking too deeply into it as anything I bought on 4K disc I wanted to have max quality playback anyway, without re-encoding.
IMHO the easist combo for regular BDs, when I’m traveling to a country where it’s legal to archive your purchased media, is AnyDVD HD + Handbrake.
MakeMKV has a forum and a UHD faq
https://forum.makemkv.com/forum/viewtopic.php?f=12&t=16883&sid=4fc64946d9f5c9c301ae23b3e2897b81
Have you played UHD discs on your computer? If so, how is it?
My set top UHD player, a Sony UBP-X700, is a bit of a POS at times and loves to freeze up and skip when playing certain 4K discs. Since high end players are pretty pricey, I’ve been contemplating just getting a UHD drive for my computer, since I know it has the hardware to handle it, and it’s hooked up to my TV anyway. I just wondered if the DRM and software front is a pain to deal with.