Didn't add weight, just moved the battery pack back to move the CG from 3 1/2" to 4 3/4". It flew inverted well at the first CG at quarter throttle. It's been raining here in UT so we haven't been able to try inverted at a higher speed. As for more planes, working on 3 right now! We are going to try to crank out 2 SPADs tonight.