ORIGINAL: psuguru
Even if the linkages are all tight and stiff and not bendy at all, the surface can STILL flutter if it can be flexed away from the point of attachment of the horn (ie the surface itself is not stiff)
True, but this is VERY RARELY the cause of flutter on these small 3D planes the OP is talking about.
And even then if this does occur a better fix is to re-inforce the flexy area with an inbedded CF rod or other similiar technique, that is actually effective.