As far as I know the small white spots are molds that are grown in bark, it will undermine seriously the root system of orchids.
Whenever I discover the molds in bark, I will repot and reduce the frequency of watering especially in humid weather.
I had a bitter experience to divide a big Phrag into five, I spent 3 - 4 hours to separate the long roots that twisted together. I had viewed a video that a Taiwan orchid grower just cut the Phrag with roots freely.