After a lot of set-up flights I think I found how to ....!
My problem was that the heli was pitching up dangerously in forward flight and giving nose down orders was low and not complete
1K500gr more weight in the nose to get the heli centered ( nose little down when lifting the heli ) I know it's a lot but ....!
100% head gyro AND increased gains to maxi 20 ( instead of 16 default ) on roll and elevator No oscillations at all .
Finaly withdraw rate to 4 instead of 5 to help the heli not pitching up in forward flight ( mostly facing the wind )
Here it is , tell me what you think and if you see something wrong or missing