That type "sump" is exactly what I was discussing. I'm surprised at that large of a hole... but they may want them that large so that the fuel doesn't JUMP the holes as you go with side forces etc... too small of a whole and the fuel could just skip right over it.
I haven't researched that yet - and would do so BEFORE I start my mods. My original thought was to "fill" the area covered by the sump with .5 or .75 holes... so it'd look like swiss cheese but still have "some" structure. I have some very cool Hougen RotaCut Broaches from 5/16" up to 3"... and they'll eat stainless all day and make a perfect undistorted hole. So I can make the proper size and pattern for whatever is recommended.
You're on the right track...
