A few shortcuts would be nice. But a option to use automatic bookmarks or not, are needed. And possibly how long the bookmarks whould last.
I disagree. MC could always save an automatic bookmark unless a manual bookmark is inserted. Because MC would not automatically use the bookmark this would not bother anyone.
Currently MC's Bookmark field shows a playback position counter that works with audio too, but the last position is saved only on video playback. With a "go to" button this could be extended to audio.
If the automatically saved bookmark would be a separate field from the counter then it would be possible to start playback from the beginning and after a while go to a previously stored automatic bookmark.
The bookmark marker could have a different appearance depending on if the bookmark is saved automatically or manuallly.
Here is a new mockup. It has only one button with a tooltip and right-click menu:
The right-click menu could be like this:
The reset button is needed for enabling the automatic bookmark saving again if a manual bookmark exists.
Perhaps the Theater View mode would need an additional option because it does not have the standard playback controls. For example: "Start video and audible playback automatically on the bookmark position when in Theater View."
However, if my suggestion is not possible then a general option for disabling the bookmark system would be needed.