Everything is saved. If you save the tournament, exit, restart, and reload the tournament, it should continue exactly where it left off. Always from the last point you saved.
Auto-save is your friend. I would suggest setting auto-save to save once every 60 seconds, personally, because why not? If you do need to exit and restart at some point, you'll always be within 60 seconds of the last time it saved. Also check the box that says "Save after significant events". That adds additional save points anytime anything significant happens, like someone busts out, or buys-in, or rebuys, or adds-on, or the round changes, etc.