JACK transport for e.g. film music
A very cool thing to have would be JACK transport in MuseScore.
It should work approximately like this: There should be a small tick box somewhere that switches JACK transport in Musescore on or off. When it's on, MuseScore and all other programs that have JACK transport enabled should behave like this: I put the cursor of MuseScore to some specific position and start playing, and immediately the other programs play at the same position.
This feature would be very useful to write film music since there are movie players like xjadeo that have JACK transport.
So here is my deal: You write the JACK transport and I will alpha-/beta-test it and write a film music tutorial in english and german. :D