yeah....

This is how I dealt with moving batteries backwards, its not the cleanest and was done after few flights when the plane is ready

the batteries are the yellow thing under the red pushrods.

I had to add more then 1 oz to the tail, and I still need more, I’m fixing a tail dragger soon.

I placed the batteries behind the servos.

Glued Velcro to the bottom of batteries, at the last former and a strap to hold it to the former.

It flew like this and nothing moved or released. [8D]