After extensively testing of
all I can say: You can tether older Phase One Backs like the p65+ only with Catalina (the latest Windows 10 version is prior to build 1903).
More recent OS versions will show you a screen of death / kernel panic after a few seconds. Apple dropped FW support with Big Sur in November 2020 – maybe only a few devices continue to work for whatever reason. Capture One works only until version 20 as they consecutively removed FW support in December 2020.
So connecting an old Phase One Back to a new Macbook + OWC dock under Catalina (!) is possible but not recommended. Using a late 2014 Mac mini for 100€ is certainly a better choice if you need to transfer only images immediately after shooting to a network drive.
The FW tragedy continues …