Av8r
I did not do retracts. I added a second 1700 mAh Rx batt, two rudder servos and an additional hatch and mine came out at 15 lbs dry.
I did not do a hopper tank on top of the 50 oz main but I did add the BVM UAT in the front compartment under the ECU. It also balanced right on the indicated CG with the UAT full.
Roy