The major update here is the in-game scenario editor (accessible from the main menu).
It is a very early prototype, and you will still have to make some edits to the scenario json file yourself (just to add a description, set the scenario start time, and the player initial spawn location) - but overall it is much quicker and more convenient than manually editing CSV files. I just did a live stream and created a basic El Reno 2013 scenario in about 20 minutes.
I have also split the y-axis inversion option into first-person and vehicle third-person options.