Peterh337;
Now you are entering into an area of serious arse covering. With the ambulance chasing lawyers there are in the US the FAA had to come up with clear instructions rather than grey areas, and rightly or wrongly they went for the most restrictive they could so that if a pilot went flying with a bit of ice it was his fault and the FAA could say "told you so" in court, EASA is going exactly the same way and I can see things getting a lot worse.
TKS is a good fluid for de-icing, Ive just never found a really good TKS system on and aircraft. Hot intakes and leading edges for me every time!