ColeTrane,

I've read some of your other posts on this topic. What is "DT" and "RT", please?

Okay, never mind. I assume you mean down thrust and right thrust.

OP from Flycatch: What you are describing sounds like a classic case of nose-heavy to me. At slow speeds, the decalage is taking care of things, but at higher speeds (your three-quarter throttle setting), the decalage becomes more pronounced, and you then have to correct by reducing it with some down elevator trim. The fact that you need to carry a lot of down elevator in inverted flight substantiates this suspicion, as that is also an indicator of a nose-heavy condition. Running out of elevator in the flare clinches it for me. You need to move your CG back.

And yes, I agree with others here that you need to know how much decalage you have, and how much incidence you have in each wing.