Hello Mike
I believe I have shared this info. before on this forum.
This may not be your issue but it is easy to check with 4 foot long sticks clamped to the bottom of your flapperons as outlined in the model 2 manual.
As has already been mentioned, check your flapperon rigging at the position that you cruise at.
I also have a Model 2 Kitfox that I have been flying for 19 years.
The first 14 years with a Rotax 532 and then I tried a Jabiru 2200.
Since my Model 2 did not come with an elevator trim tab, I trimmed for cruise using minor adjustments of the flapperons.
With the added 20-25 pounds weight of the Jabiru the CG was still in range but now more forward.
I compensated the nose down tendency with trimming the fapperons for hands off flight in cruise as I always had with the 532.
I just did not realize how much I had reflexed them for hands off flight.
The old Kitfox kits did not make provisions for flap lever positions like the newer kits do.
What used to be a fun airplane to fly became almost miserable to fly.
The ailerons became very heavy, one wing became heavy, the stall speed increased and coordinated flight was difficult.
Then I experienced scary flapperon flutter in turbulence and grounded the airplane.
I asked the same questions you have and was given the same advice which is all very good and I followed.
Then a Kitfox owner in Idaho asked whether or not my flapperons were reflexed.
I went back to the manual and found that my flapperons at cruise were refexed way out of specs.
I have since made a mark where the flap handle should be when the flapperons are rigged properly.
The airplanes former good flight characteristics immediately returned except I needed to add weight to the tail to trim the airplane (or a trim tab).
I have not had flutter since but admit I get nervous every time I get into turbulence.
It is embarrassing to admit that I fought this problem for almost 2 years before the flutter incident grounded me and I did not make the simple connection between flap handle position and bad flight characteristics.
I thank this forum for my solution and hope you find the same so you can enjoy your Kitfox.
Herman