OTT reaction
It is hard to see the talk of errosion of paint (& props), the damage to the inside of engines being very well informed when directed to light aircraft flying at low levels when the "ash" is above FL100 or more likely FL200.
The small amounts of "ash" that might fall to earth are likely to be so small that it is likely to be pushed aside by stagnated air ahead of a slow speed aircraft.
As to the dust damaging the engine, just observing the differance between the dirt washed out of an air fliter in the summer vs the dirt from an airfliter in the winter will show just how much dust is floating around during the summer as well as how well the airfilters remove fine dust from the induction air. I have yet to see people on these forums recomending that we dont fly in the summer due to the dust!
So given the fact that there is very little volcanic ash at low levels, the aircraft has a good air filter and that the engine works in a diferent way to a turbine there is very little chance of engine dammage and no flight safety risk. In fact the flight safety risk is probably lower due to the lack of other air traffic.