Don't get ahead of yourself. No track will play "more often" - shuffle will only play each track ONE time. You have to re-shuffle to get the track to play again. So what you're doing is getting your favourite tracks to play near the top of the list, not "more often."

I just thought it would be a good idea to point that out before we get into confusion when talking about feature requests and what's currently already on the table.

If you want something to play multiple times you can insert or append it multiple times as mentioned elsewhere (I think someone's already linked to that thread).

Bruno