RBean, Yea wing separation is not pretty. Seen it a few times. I started to put Zenoah G20 gas engine in but decided on Saito 125. I like your upgrades. I noticed looks like you did not put in the H9 wheel wells. Even cut out more of the wing to allow wheels to set deeper? The H9 supplied tires do not go down completely, too wide.
I did not install the H9 wheel well doors as we fly off grass field and concened they may cause problems.