In considering the wings and ailerons as a ‘system’ it is worth observing that the aileron hinges on WW1 Sopwiths were the same as 1930’s Hawker biplanes. That is, a ‘fixed’ hinge where the aileron was actuated and ‘sloppy’ hinges at both extremities. When the wings bent, the sloppy hinges allowed the aileron to continue to function, rather than cause binding. Following this, the aileron spar would ideally bend in the same way as the wing spar, to prevent binding. So a more rigid metal aileron might cause binding as a more flexible wing did its thing. I am not up with new fangled monoplanes, but I figure more rigid wings for high speed performance would allow more rigid ailerons. The timber Mosquito wing had metal ailerons and hinges which did not have slop. There were issues with recovery from high speed dives for Mosquitos with spar failures outboard of the engines being a characteristic and operational limitations placed on this as a response. I do suspect Hawkers had a lot of wisdom in their design choices. I do note Cessna 152s have piano hinges and metal ailerons which I guess flex but theres always a lot of metal powder that seems to leak out of them and the thin wire inside the hinge seems to be sacrificial, like student pilots.