I don't know about the hinge "mis-spacing" idea, but it got me thinking/drifting - Not versed in this area, so pipe-up if I'm conjuring up some invalid concepts in my mental meandering.

First lets assume that a flimsy control surface or sloppy linkages are not the problem.

Assuming a relatively slender panel, e.g. an aileron, when flutter occurs, is the entire aileron fluttering uniformly about the hingeline, or is it actually rapidly "micro-flexing" about its chord axis (like a vibrating beam) with maximal deformation occurring near the TE? I believe the latter is the case, at least for slender surfaces - I hear a lot more cases of aileron flutter than rudder or flap.

Is flutter strictly structural resonance, which is a function of mass and stiffness, or is there also some aerodynamic influence like vortex shedding off the TE? If the surface is resonantly flexing about its chord axis, could varying the stiffness or mass along the length of the panel make the surface less prone to flutter all at once along its full length? Such a surface could be made by "simply" making it from different grades of wood or composite lay patterns. Seems like the surface would then be prone to flutter only at localized points at a given airspeed, but not the whole surface going into flutter. Not sure if that's right; I think there will still be a resonant frequency that can be triggered at some airspeed where the whole surface goes into flutter despite the variable section properties.