If'n the model balances out in a static test (and most will not) then the last thing I do is add any unbalance setup such as tip weight
One thing lot of aerobatic guys do NOT do , is to balance the airframe about the prop axis
For those who wonder if this really counts - try some good ol flat foamies with the battery mounted high -above the wing and low below the wing
Now do your full routine of rolls snaps etc..
It can and does make a difference on hard core aerobatic models.