I see the new "View in Concert Pitch" option made it into the Notes menu
on the latest pre-release!
There are a few bugs I came across using the feature.
1. Currently the View in Concert Pitch option is Undoable. Undo reverts
to the previous transposition but the check mark next to the "View in
Concert Pitch" is not updated.
2. View in Concert Pitch transposes playback as well as display.
Playback should remain unchanged.
3. Often the transposition is handled incorrectly so toggling View in
Concert Pitch takes you to different key signatures each time. (See the
horn part in the file attached for an example)
4. If you save the attached Brass Quintet file in your template folder
and create a new score from it (via the New Score wizard) the Horn part
has a different key signature than it is supposed to. It has one sharp
in the original file, but six flats in the new score.