Hello dowdds,
To add to larason2's reply:
Hauptwerk v6 itself should work on macOS 11 ('Big Sur') on Intel-CPU Macs subject to a few minor/cosmetic known compatibility issues with macOS 11, which are listed in the 'known issues' section in the release notice:
https://www.hauptwerk.com/documentation/The only additional issue we're aware of is that macOS 11 seems to need a bit more of the RAM for itself, so if you were almost entirely filling the RAM with an organ in an earlier macOS version, then you might need to tweak some rank memory options to so that the organ uses a bit less RAM. (Strangely, in macOS 11, if the RAM is over-filled you might get no audio output:
viewtopic.php?f=4&t=19665#p147468 .)
Best regards, Martin.
Hauptwerk software designer/developer, Milan Digital Audio.