I too cant wait for more test results of this type of set-up.
And yes i cant see 100% gains but 30 to 40% or more would be great and probably will be in the ballpark.

There are many possible set-ups like.
1 a shroud in between the two rads with fans in a push/pull on the outsides of the rads.
2 simple and basic fans in between both rads.
3 Fan>shroud>rad>fan>shroud>fan>rad>shroud>fan
But that would be WAY thick and probably overkill.
It would be a wild set-up though.

I wonder if #3 could give almost a 100% gain?

I would like to see these kinds of test