About Anti Ice and what I figured out in AUTO:
When changing altitudes rapidly and dramatically the compressor (that produces warm air) can’t follow the rapidly changing values generated from the ice detector.
Nice test: perform all HARTS quickly after each other in AUTO in bad weather (outside temperature of approx. 15 Celsius at sea level) and soon you will get a warning that anti icing is not working anymore. To avoid this… set the switch to ON
When cruising about the same altitude it’s fine to use AUTO.
I thought I red something about Engine Fire after half an hour of being airborn…? Of course more cases can cause engine fires, but when there is/was nothing going on it highly possible that the Air Source is not set