I have- back in 1996. My husband and I were part of a focus group for the ideas for Test Track. It’s been a while, so I am sure the procedures and things have changed, but we have both sworn if we ever get the chance to do it again we will.
I would imagine by the CM's near the front gates who stop random people to ask a few questions about themselves. Never knew you could be contacted further and attend a feedback session.
Interesting. Last month was stopped exiting EPCOT and taken to an area going towards buses that had been partitioned off. They had me sit and take a computer survey. Was some interesting questions on it regarding my opinions of integrating Disney characters and movies more into the World Showcase.