I think you are correct, at least that’s how I put mine in, (But! it is not tested yet...) i.e.
The bigger of the two flat sides to the right when looking at the board from the front.
You would think they would have fixed the silk screening when they got rid of the N0MOS board that replaced U3, the TA7642.
Also it seems like they want you to wind two of the toroids in one direction and the other two in the opposite direction. Nothing in the instructions about it, it’s just the way the holes in the board are arraigned. I wonder if it matters.
I am impressed by the spacing and how everything fits together. Almost got the 10uF and 100uF electrolytics mixed up, mine are the same size.