Thanks, Andy.
I read the 3x3 almost like a GT actually. I look at the core (focal card), the "cross" - on both sides, above and below the focal. Then I take row by row, column by column and diagonals. Basically all the stuff. usually the core+cross is the key info. The rows and columns juts tell stories like phrases or sentences. Diagonals sometimes add something, sometimes not so much, depends really.
Honestly, I think you should try and see in real life what will work for you. It's a nice spread, one of my favorites, not too big but rich in info and you can easily follow how it plays out in reality. I do it every week, a weekly draw. This way I can follow how it plays out and know where I was wrong quickly.