It seems there is no way to mark a checklist task or a complete note as Done by adding inline tag #done or #done(28 Oct 2018). After adding a #done tag the text of the checklist task could be crossed out.
Furthermore there is no way to build overview searches with filtering (in or out) Done notes.
This isn’t TaskPaper. When using a new tool, you should logically expect to work with it in a new way—possibly contrary to old habits.
It’s perfectly possible to mark checklist items and entire notes as “done,” with both the mouse and the keyboard on Mac and with a quick tap on iOS. You just can’t use tags to do it, and there’s no objective argument for needing to do so.
It is true this is not there yet. We have some ideas about this type of “command”. May get to it in future. Thanks for the feedback.