I was thinking there would be more detail considering the years between the releases. I felt like the ashcan version didn't really fit my needs but I'm still not sure what changed since then. For example, is there any change to how a mystery is built?
If the ashcan didn't fit your needs then the full version probably won't either.
How you build the mystery is something that hasn't changed between versions. The biggest addition to that was the TPG Clue Chart where it can help you create clues that don't necessarily make sense out the gate but can be interesting as you play.
There's an essay on ACAB. There's suggestions on how to play collaboratively better with some tools and conversations... it's got a better section on RPG safety and we added another layer of mystery but if how the mysteries were created weren't your jam then this probably won't be either.
No worries. Also direct questions are easier to answer. ^_^
This is something we did clean up from the Ashcan but it wasn't a wholesale change so that's why I didn't think to include it.
When you place clues to the mystery there is a move for that and it's a basic move called Putting It All Together.
What I did was clean up the language on what happens when you get a 7-9 or a 6-. Before the language only made sense if you had a GM where now we talk about how the other people put it on a suspect that will impact the character the most.