I have the latest XFLR-5 thank you. I am talking about so called form lift vs form drag. Like in Wortmann FX 63-137 they have L/D 137 at 2,5 AOA @ 1 mio Re.
Anyhow...what I discovered is is that when you put a man like me flying the HPA ( 260 LBS ) you need to make craft at least an 70-80 pounder.
This way you start to create some believable speeds like 15 m/s...it is a huge difference in lift between 12 and 15 m/s.
Also you can design the entire aircraft make lift ( using the knowledge by DeMonge and Burnelli ). Kinda like a recumbent. This way the entire drag of the "man-box" disappears as it will be part of the lift equation.
Prop being 2.8 m is enough.
Having the wing area like in Musculair 2 is not enough, but lifting fuselage derivation will add amble of lift in ground effect.
I would also take the measures from the prehistoric bird above for span vs length ( 5:1 ).
Main idea is increasing lift area thus diminshing the induced drag....parasitic drag does not increase.
I tried to beat the Wortmann foil with mine but "only" got L/D 142 at @ 1 mio Re.
Looks like the Lissaman 77xx(ish) is very efficient.
My apologies then, you must have posted an old screenshot of XFLR5 then, as it shows 6.48 in the corner and latest is 6.57
The drag you mention doesn't seem to be calculated correctly, after all there is no free lunch in physics.
Have you checked out the Ultralight Airplane Workshop at all for tutorials on this stuff? I apologize if you're an aeronautical engineer, I just found it very helpful is all.