Heavy flutes
I have been chatting with another RV10 builder in GSO that's a good friend of mine, and a first time builder. He messaged me last week about a section in the plans that said to "heavily flute" part XYZ (I don't remember the part) and I advised to do as it said..worked fine. I built a -4, which had zero holes, every rib and frame warped (a normal effect of forming/heat treating), and I had to flute everything prior to fit, layout, and drill up. The -10 and other match drill kits have the rivet holes drilled before form/heat treat, and the fluting gets things back aligned.