It is still a good investment for sometime down the road. They will be making pennies and nickels out of cheaper material. When that happens, I believe they will allow the meltdown. Just like silver coins; they make them out of cheaper material now and it is legal to melt the silver ones.
I read about it. They didn't seem to mind back in the 80s when we were turning in roll after roll and hoards of silver coins to be melted down because the price of silver went so high. At least I don' recall any problems.