RE: Best CG for a focus
There is much more than CG as far as impact for spins and stall turns.
Now, before I changed wing incidence, I mixed in some right aileron mix with low throttle. This kept the wings (and plane) tracking straight in a spin entry (particularly inverted spin entries, since at the time it was tough putting in left rudder when approaching the spin entry). I think I remember doing a mix condition on my Dr. Jekyll so that with the gear up, and on high rate, the mix would go in (elevator). That way the elevator trim would not change on landing approach from what I was used to. I remember now that I also used to put in 1/8 inch left rudder trim activated with high rate switch for the spin entry. This would keep it from "breaking" to the right... The issue with the idle-to-aileron mix- I found that the wings would (very slowly, like 5 degrees to the right) drift at/during the bottom of a pull out. Example would be at the bottom of a square loop, as the plane pulls out of a vertical down line to horizontal, (going fast) the plane would roll slightly right as its going fast...
So I discovered in 2003 the one application that I have effectively used negative wing incidence, but only on the left wing required about 1/8 inch negative incidence..
So the left wing neg incidence requires right aileron trim for straight and level cruise speed flight, and as the plane slows down that right aileron trim takes over, resulting in a nice straight, stable spin entry (either inverted or upright).