Just fly it. I gave up on actually measuring the CG point a long time ago on 3dhs planes. I build them, stick the battery about mid tray and go fly. Adjust battery as needed and fly more. On mine I think my pack is about 1.5 inches forward of the wing tube. I run a 4325 also, xoar prop, plastic ExtremeFlight spinner, BEC Pro mounted to front of firewall, and my batteries are ~760 gram 6s5300's.