Playing around with XFLR5 I had a good time with inviscid flows, but no such luck with viscous flows. Either way it helps with visualising flows. I don’t know if the vorticies around the fuselage you see in the following images are that true to form at 10m/s. At 20 m/s (40kts) it’s probably more real. Then again we can’t expect too much from 90 degree corners anywhere around the front of an airfoil.
All in all I think 7 degrees for the wingtips will be fine. After all this is meant to be a rough wing just to carry some extra weight for the FPV head tracker.
Interestingly it seemed to say the centre of lift was around 330mm back. We’ll see how that goes.