I remember trying to take Lennon's theory into account on a canard project years back. I had no luck with it and decided it was hogwash, rather than downwash.
Of course I ended up with a canard raised up like yours, to help reduce any downstream effect on the main wing.
I finally ended up with about a 130% loading on the forewing, as I recall.
I will be watching with interest to see what you find out on this. There are a lot of bogus theories and formulas around on canards, as you surely know. Maybe you can resolve it for us all.