Flutter bothers me. Here we are in a trim thread and already 50% of the posters have experienced flutter. More than half a century ago I learned about pushing a trim tab against it's highest loads has a tendency to create flutter. IF you have a single wire or rod moving a trim tab it
must always be pulling against the direction of the highest loads. IF you must use cables it is much better and safer to use two ... both pulling to move the tab. Similar to that used on the Aeronca. The air loads against a displaced tab can be extremely high. These loads if operating against a pushing wire or rod can cause the pushing materiel to buckle or break. Whenever you have a free floating tab, it will in turn move the surface to which it is attached. Then depending on the frequency of this motion it is possible for some component to fail. It could be the tab which fails, it could be the elevator which fails, it could be the stabilizer which fails, it could be the elevator control system which fails, any number of components could fail with fatal results. This failure can happen in a matter of a very few seconds. It can happen so quickly, no matter how much of an ace pilot you may be, you will be helpless to prevent disaster.
Watch this video starting at 1:06. 2 seconds later the aileron is gone from the wing.
One of my flutter experiences was a thin .080" aluminum tab flexing flutter which in turn buckled the push rod which in turn destroyed the elevator. At this point the flutter stopped and a safe return was made to the airport. The next flutter experience, the tab push rod broke, the tab fluttered, which fluttered the elevator, which in turn violently pitched the fuselage up and down. I was able to reduce speed to a minimum which reduced the oscillation frequency. The flutter continued until the wheels rolled on the ground. That airplane had a lead balance weight on a arm to balance the elevator. The arm was twisted like a pretzel and had been rubbing on the elevator cable. What would have happened had that arm broken the elevator cable? It was close. Had it moved to one side it could have. Would the parachute I was wearing saved my life? I am so thankful, I didn't have to test it.
If you want to use tabs for trim, consider the separate tabs under the stabilizer on the early Taylorcraft. At least if they fail they will not flutter the elevators. Remember these are only for trim, not control. The trimming stabilizer on the Cubs works very well and has done so for a long time.