CA X12
Can't change the deck plank overhang.
I have it set to 1-1/2". and it doesn't update from the factory default of 1/2"
The planking is generated in the Room> Structure> Floor> Planks, Joists> Edit dialog
Not in the floor finish section. (Been there, done that)
I changed it in the room type defaults as well as the room specifications. I also have the auto framing turned off in both.