The Tough Guard filters are very lightly oiled and can hold more dirt/dust. The media is also a nice yellow color, too. Part number will start with TGA instead of CA
If the ash is that bad, it will certainly be better
Never hurts to change it. I was in WA state when Mt St Helens erupted. No filter could handle that volcanic ash. Thousands of engines were ruined. The only ones that could do well were the old oil bath filters. Changed them daily.