Very little will be left considering the impact speed. Even if the aircraft was equipped with a flight data recorder (black box) then its structural limits were probably exceeded.
I wonder if running the data cable through the foam would cause problems like letting fire/fuel/water through the helmet and disolve/melt the plastics or if you whip a cable hard enough it can cut right through things like a weed wacker.
or just ultra-thin wires connecting the memory to the outside. the ultra-thin wire will just snap and it's too light to cause damage by whipping around
the big problem is kinetic impact, fire/fuel/water would be easy to solve, for example fire requires oxygen which will have difficulties getting inside through a tiny hole, and I'm sure there is some metal alloy which doesn't melt in typical plane fuel fire temperatures