Danny
Presuming you are building as with all the detail I think it comes down to wire you use on the Afterburner set up, heavier wire pulls it back a little. It can definitely be built without weight, you can see my set up, if I had used the 5000 PB Rx packs I could remove the small amount of weight I have in the nose. It’s an aeroplane with a small tail, so it can fly like it’s nose heavy, but it’s just the lack of ‘stabiliser’ balanced front of the rear wing tube is 27cm and I would not go further back than that, when you stall it it needs flying out at this position. 28cm with half a main tank is the sweet spot.

Dave