Seems to run great, of course with some errors. Nevertheless, Files, Calendars and Contacts seem to work great. Recommended Calendar command was a bit off, but solvable.
The support for MAC was dropped since they discovered that there can be data loss. I would be extremely careful and rather use a linux system. With virtualization, this is not a huge problem, I am not sure if docker could do it as well. You can check the ownCloud repository for the original problems, I think a few were related to encording stuff in the filename (not sure if case-sensitivity was an issue or just special characters). There might be other issues as well. And for sure, nothing is tested for Mac.
Tried 2 different docker versions with no success. QNAP bloated their software and pointed fingers at Own Cloud that it was their problem 8.04 was never updated to run on a QNAP device; however being around long enough I know better. I tried installing this on Linux Mint that I installed on my QNAP, one SSL problem after another. I had tried Fedora before that with even more problems. I had it sitting on my MAC, put in a Nextcloud folder in my websites directory, modified my htaccess as recommended, modified my virtual servers file gave it a try and it worked immediately. Hardest part was getting Caldav to MAC OS working. I currently am running with one false fatal error on a Jupiter Notebook file. The file transfers fine between three different computers . . .and of course the file integrity checks don’t work (it has some c:/sqlite error . . . I guess it thinks I’m running windows . . .I’ll figure it out and get it cleared), and the card CalDav well know stuff says I’m misconfigured, but it works fine.
Bottom line, I’ll take the risk. It it fails I’ll let you know. So far it has been perfect except for the seemingly false log error and warning.
Good luck.
Using Mac OS at home on any device. Except my cloud > RaspberryPi with debian. Rock solid.