Welcome to RCU!

I have been known to fly a few planes that, like myself, carried a few extra pounds, and here is what I would do...

Move the battery as far back as you can without having to jump through too many hoops. Then add whatever weight is needed.

Now FLY THE PLANE!

Hell, I've had a few planes that flew BETTER once they got heavier.

Now this is not always the case, and you may find that you need to jump through a few more hoops later to lighten it up a little more. But why go through all that if you don't need to?