I was thinking of this thread only last week as we entered the circuit for Catania in Sicily, on a good clear day. Mount Etna nicely smoking away (as it usually does) about 10 nm off the port wing.
I just wonder why the ash and lava thrown out from that has long been of little consequence to aviation; when we got to the visitor centre a few days later there was much evidence of the recent eruptions (including one in 1971 which completely overwhelmed the old visitor centre, the tops of which can be seen sticking out from the solidified lava !), and photographs of a huge ash cloud from 2002 taken from the International Space Station. But does anyone remember any disruption from these ? No, thought not.
Regarding the FAA's comments, they had a major experience with the Mount St Helens ash in 1980 (ash so thick that they needed to get the snowploughs out to clear the roads hundreds of miles away), which was well handled and no aviation problems arose. Perhaps those who did the good job then have all been sidelined by a new generation of overcautious bureaucrats.