According to the referenced page, the Mac driver for the Phaser 6600 receives a "1" meaning total compatibility with Big Sur. But I've received some PDFs which give a postscript error: "ERROR: invalidfont" but which print just fine from a Catalina machine on the same network. So it's definitely a Big Sur issue. Please advise.
Attention Mac Users: The macOS 11 Big Sur was released in November 2020. Please read the latest blog Big Sur Compatibility Document Update to review the drivers that have been released and any additional information available about compatibility.