I set up my Omnifocus windows up so that the sidebar is invisible. The next time I log out and log back in again, all or at least some of the windows have the sidebar open again. Is there a way to change this behavior so that the sidebar remains invisible?
All built-in and custom perspectives have a setting to “Keep sidebar hidden” (except Inbox, which doesn’t have a sidebar). If you check this checkbox, the sidebar will be hidden by default.
For example, if you generally don’t find it useful to see the Forecast sidebar, you could check the “Keep sidebar hidden” setting for the Forecast perspective. If you quit and relaunch OmniFocus, the sidebar will be hidden by default.