I am quite sure the angle is to counter act the torque of the motor ,mine was hand launched ,so I had my elevator
slightly trim up to counter act with the plane drop as I threw it in the air ,it was a size OS 15 engine so it had some
weight!
You can also check an make sure that the CG is...
They do put a little thrust angle in them ,yours looks a little extreme!..🤔
When I built my nitro foamy ,it didn't have the side angle ,it had the up & down angle in which
the prop was pointed slightly down but not much!
I can't help ,but you might just have to experiment with it!..😎