Yeah, I've got a pretty solid plan for the benchwork (until the joiner tells me it's not, heh). The plan there is at 18" depth which seems plenty in N Scale. The last module I built had a width of 12 inches so it feels like plenty of space. Perhaps 24 in a few spots.
OK, I think I'm going to go back to the drawing board on the industrial port side and see what it looks like without a yard, and pay attention to the module dividers. Ideally, I'm going to shoot to have nothing bigger than a 4 foot by 18 inch / 24 inch module which I think makes sense.