I did not consider just being strip ailerons being a cause. You are right, the ailerons themselves are likely flexing . It has been decades since building and flying the first Smoothie and I only noted in my log then that ailerons at first seemed sensitive. A big difference is the age of the pilot and the time past since the first one of this design.
As I noted above, I am intending to fly with Expo on next flight so , no, I have not experienced expo reversed . That would certainly do job of making ailerons sensitive near the center of travel, though, if set up that wrong way.
When I think of aircraft with "barn door" type ailerons that I built in the past and currently, it is correct, I did not experience the slow roll rate vs. sensitive reaction initially.
Thanks for replies.
Dan