I'd like to chime in here to add my vote for this 'feature.'
Not having the ability to auto-expand the favorites tree is the last barrier to full adoption of Directory Opus 10 for me. In Windows Explorer, Favorites is the first list, and it is fully expanded. I use Favorite for everything, as it is fast and I never have to navigate through the drives. It is my defacto location to look for what I need. DO inhibits my workflow by making me expand the Favorites tree every time. Minor, but very inconvenient.
It looks like there are others who share this frustration, judging from this thread and the following threads with the same topic:
https://resource.dopus.com/t/expand-libraries/10595/1
Could you please consider making this an option sooner than later? It's been difficult but worth it to fully replace Windows Explorer with Directory Opus, but like I said, this is the last barrier keeping me from never looking back.