I too have been battling similar characteristics with my Extra Special.
(I am running a Brison 3.2, and B&B smoke system, and I think I am ~17 lbs, rudder servo in tail)

I have noticed improved 3D flight characteristics, specifically with harrier/elevators when moving CG back too. The trade off I have found with aft CG, is that on a calm day, the thing does not want to land. (Running a MSC 22X8). I'm still dialing in that CG sweet spot.

An example: I have my RX battery in the forward area of the rudder servos tray. It wing rocks hard, and if you are not ginger enough on the elevator, going into a wall can cause a wing to snap (forward CG). I moved my battery back 3”, and we noticed an improvement the following flight. I then moved it back another ~3” and elevators were rock solid. The trade off of course was landing required a few go-around before it would descend. It just wouldn’t come down. I moved it forward since then. I plan to take the smoke out again to see how is the CG combo works with the CF landing gear W/O pants. Absolute take-off weight will also impact these performance characteristics.

We need a ballast on a track, controlled by auxiliary channel to change CG fore/aft in flight then we could have best of both worlds.