EC155pilot
you are talking nuts. You seems to be a real expert.
Mi-2 is surely not really one of the best helicopters ever, it's an very old and heavy ship but it's one of the best de-iced helicopters.
Fully deiced main- and tailrotor, windshield deicing, engine deicing, pitot deicing coupled with an automatic icing indicator. Due to the engine oil tanks filled with warm oil in the air intakes the engines are additionally protected.
I have flown the ship in heavy icing without any problems. It's quite impressing during flight to see ice plates coming down the windshield with working deicing system.
The only problem i found ever is the failure of the russian built ADF under icing condition due to iced sense antenna.