You could move the battery pack towards the back You would have to cut out an opening under the fuse, and you would have to lenghten the battery leads. that's how mine is done, this way you don't have too much weight. I also have a OS 46AX another thing was to move the tank back a bit. now it is balance without adding any weight.
I know it's a lot to do but if your fussy you find a way. by the way this plane flys great.

roltech