Thanks for checking out my article. I think you must be referring to the detailed scene analysis I showed in the Inspector, where there is, as you say, Turning Point, and Turning Point Type, Value Shift, and some other custom fields. You are quite right. These are custom Properties that I have created inside Aeon Timeline.
It is possibly too much to go into a full blown tutorial here on the forum, but in short, custom Items, Relationships, and Properties can all be created in the Advanced Settings inside Aeon Timeline 3. So I created one for Turning Point and set it as a multi-line text property and then selected which Item types it applied to. For Turning Point and Value Shift, for example, I wanted those properties to show in Scenes, Flashbacks, and Flashforwards. But for Sequels I had to create other properties to show their specific information; Emotion, Thought, Decision, Action, etc.
I was hoping to have published some further articles on setting up custom types and using them to track various story elements, but we lost our beloved cat, Nala, earlier this week, and I’m taking a short break from writing as a result. But I know there are some knowledge base articles on how to set up custom elements on the AT3 website. If you have a look there and are still struggling, drop me a PM here, and when I can, I will send you a copy of my Hansel and Gretel file, if you give me your email address. It has all of the Story Grid custom elements built into it.