Can I save my preview layout?

I’d like to use the widescreen layout to preview my documents. But everytime I close and open Devonthink I resets the preview panel to the standard option. Is there anyway to save the widescreen option?

Are you saying it changes when you relaunch to the same database/group?

Different databases and groups selected in the Navigate sidebar can have their own views.
You could set up the view the way you like, then enable Preferences > General > Retain View. This will cause an override of subsequently visited locations.