Here is the latest on my “Smith” experiments:

I left the CG alone at 3/8” behind the leading edge of the bottom wing.

I changed the down thrust from 2.5° to 1° and right thrust from 2.4° to 1.2°. For down thrust reference this is with my stab set at 0° and the wings are still at -1° bottom and -1.5° top.

This is very close to the sweet spot for my “Smith” vertical up lines are stable, my loops did not try to cork screw. Recovery from snap rolls was predictable. Take off rolls were also much improved.

Inverted required only a very slight touch to the down stick to keep it flat and level. However it would still pitch to the bottom side of the plane (climb) on an inverted 45° up line. This is one of the symptoms of being too tail heavy. It still had a slight tendency to corkscrew in outside loops however.

With my particular set-up I do believe I could go back to 0° down thrust with the engine. But keep in mind that is with my wings set-up with -1° and -1.5°.

I can tell you for sure that changing the angle of attack of the wings created a trickle down effect with everything else. If you have never had the chance to experiment with this stuff it is quite interesting when you get to do it first hand in comparison to reading about it. I also believe that the bigger props that I am now running due to the engine change have adversely effected how the plane flies as well.