I'd like to export only some of my show for my cast. How do I do this?
If you're looking to export only particular songs for your cast to access via RMS Mix or Rehearsal Live Share (perhaps to save on upload size and leave things like Scene Change music out), it's a simple process to do so.
Note that, whatever song you are currently navigated to is where your export will begin - and it will run to the end of the song list.
So, with that information you have two options.
Enter Edit Mode and reorder the songs in the window (clicking/dragging them around to reshuffle them). You can then drag Scene change music or other pieces the cast doesn't need to the top of the list and start your export from whichever song you choose.
If you don't want to mess with your current show, you can do a File > Save As to create a new show document where you can remove/reorder songs. You could name this new show file "Cast Export" or something to that effect. Here, you can not only reorder songs, but you can also remove them completely, in Edit mode, by selecting them one at a time and hitting the Minus (-) button at the top of the songs window.