In both DVDFab 11 and 12, when ripping a UHD Blu-Ray, only the 3 passthrough profiles are available, plus Mobile and Theater.
The only way to be able to select single stream Dolby Vision is to select the Theater profile, as long as you have changed the default profile for UHD Blu-Ray to re-encoding (!), which is crazy.
Luckily , I can afterwards select "copy video" and still choose Dolby Vision Single Stream.
