Most likely it will flat spin and snap inverted. Right side up flats and snaps will depend on the trainer setup. But every trainer I can remember will snap and spin inverted, even if the CG was slightly forward and even if it would not snap/spin right side up. Don't worry too much about getting an extreme rearward CG on this plane. Do however get the hang of flying around with a good deal of throw on your control surfaces (which it sounds like you have done) as well as inverted flight. Then start with a few inverted spins (remember to cross rudder and aileron in inverted spins.) Get the hang of that and then start making them flat. The most common way to make the spin flat is to relax or even reverse aileron once a normal spin has established. To exit the spin, you can convert back to a normal spin and exit that; or, by sending ail/elev to neutral and applying opposite rudder and throttle will often cause a rapid spin exit.. There is no doubt a more aerobatic plane will be more capable, but trainers will flat spin. Jut be sure to practice high to start to prevent a splat spin. Cheers.