The mighty C-5 had NO TAI for the wings and apparently didn't need it. I've flown trainers for 4 hours in winter conditions, at 0C, with no accumulation. And approaches in Germany, in heavy wet, cold weather with no icing.
OTOH, ice in a Beech Baron, flying checks in the lee of Lake Ontario, was a fearsome problem. Scaler properties, I guess.
The manufacturer of the GLEX says CAI and WAI ON in icing conditions, I don't go against the book, turn it on and haven't seen any ice.
GF