Yes I did try fitting the dual fuel sediment bowl to the starting tank as well, but same problem, lines would come from general front and right.
Looks like all the site I've found only sell lines for the 12/3 bowl, but then only sell the 9/3 bowl.
I'll get a 90 degree elbow and that should solve the problem. It'll be hidden behind the battery box, so shouldn't look too hokey!
Diagram shows a shut-off valve T on the starting tank, incidentally, I called CASE-IH and they do still have that T for sale, for $150+ !
Decided I'll put the dual-fuel bowl under the big tank, and use the single outlet bowl under the starter tank. That single bowl would have been destined for the trash and is free.