GOOD ONE !!
Had to take a dump ; had to hold it till the end .
In regards to your question :
Yea , best way to reduce interference drag, is to just get Rid of the intersection ; why
do Ya think they invented J-foils ?
Second best way to reduce interference drag, would be to estimate the AOA
on your main foil , and make a symmetrical cross-section that interfaces with
the strut or body, that flies at (O) AOA to flow, and tapers into your wing-profile.
And the third best way, would be to use a wing profile at the body/strut interface, that
can fly at same AOA as main wing, but with Less drag for a given AOA.
Now the example given in #2, won't be producing negative lift at start.
LOOK at how the Humpback Whale does it :