In the @monday podcast, I think @artkavanagh said that he didn’t find the way to cross-post a category to Twitter. But there is. I found that you can go to the Categories page, select a particular Category and copy its xml feed. Then in the Account settings, under ‘Edit feeds and cross-posting’, it is possible to add the previously copied feed and link that to Twitter. That way, only posts included in that category will be cross-posted to Twitter.