Personally i like to balance with the UAT full for the peace of mind that i can shift the UAT and balance without the necessity of dead weight (that's a biggie in my book). i know occasionally I'm gonna have the left stick in the FUN position too long and suck the UAT dry and flame out, but it's never been a problem of a major CG shift when it happens and i've had them tucked in the nose and in the tail on different models to achieve balance. most airframes that 4oz really doesn't make that much difference. YMMV