orion may happily remember if I have or didn't have the sidebar opened before quitting the app but it doesn't seem to be able to remember that I wanted it to stay at the bookmark sidebar tho
or in another word;
leave sidebar open at bookmarks list, close orion, open orion again, the sidebar is still there but not at the bookmarks list anymore
i'm currently on 0.99.123.1-beta
(don't mind if I'm using this as a workaround for that there strangely seem to be a one-column history menu but no one-column bookmark menu, i'll prefer to not complain too much about this particular item for now nevertheless)