For my RV-8, I had test flight cards for each flight while in Phase 1. Although the Vans series have a proven history, each plane is very much an individual. Phase 1 is used to root out these differences and to document performance. Of critical importance in a tandem seat configuration is to test various CG conditions before putting live people back there. My -8 was a totally different aircraft when at max rear CG...best to learn how to manage this with sand bags and not human souls.