beachbrada:

I would suggest moving the CG in the opposite direction, to the tail, even beyond 5" from LE, if your tests still indicate nose heaviness.
That is something to be done in small increments, being alert for any sign of tail heaviness (touchy elevator).

For level flight, you get the balance around a CG that is too much toward the nose, by trimming the elevator up, so the wind pushes the tail down at cruise speed.
When going into KE flight, the elevator trim that tries to pitch the model remains, but the effect of the CG does not match it.
For inverted flight, you get the balance around a CG that is too much toward the nose, by elevator down input, so the wind pushes the tail up at cruise speed.

That is the coupling desirable for a trainer, but not so good for an aerobatic model, which is trimmed (to the very limit of tail heaviness) to go where is pointed, with no auto-corrections.
Most of the available trimming charts are for aerobatics.

Good reading about this here:

http://fatlion.com/sailplanes/divetesting.html

http://fatlion.com/sailplanes/decalage.html

http://www.charlesriverrc.org/articl...GMarkDrela.htm

http://www.dubai*********.org/flight_trimming.htm

Regards!