Note: for the sake of brevity I'm going to assume you've read the Valeria Loves review of Fabula Ultima, since I'm writing this with the mental context of "Fabula Ultima as Ema expects it to be played."
As of writing, my Fabula Ultima group has gotten through session zero (which, as I'm learning is pretty standard, ended up being two sessions) and three sessions of adventuring. I won't regale you with the details—as I said in My Lessons 0, I don't want this to be a direct after-action report—but according to my players they've generally been enjoying the experience, even with the usual system growing pains. Now that rubber's met road, though, I have a better sense of both what I'm finding difficult, what I'm finding easy, and how I'm having to mess with the rules-as-written to better fit what I'm trying to run. So, I want to take this post to collect those thoughts and maybe sketch out some general takeaways.